Picture blistered Brussels sprouts, their emerald edges bronzed and crisp, nestled beneath a blanket of bubbling Gruyère and Parmesan that perfumes the kitchen with nutty, wintery warmth.
Imagine slices of herb-basted steak—edges crackling, center blush-pink—laid over a creamy, golden gratin that’s both velvet-soft and breadcrumb-crunchy.
This is the kind of meal that steadies a long day and turns an ordinary evening into a little celebration.
It matters to me because it marries comfort and polish: a single skillet, a short list of staples, and flavors that feel restaurant-fancy without the fuss.
It’s perfect for busy weeknights when you need reliable payoff, or Sunday suppers when you want seconds and stories around the table.
Once, after a late soccer practice, this gratin-and-steak combo landed on the table in under an hour and kept everyone—picky eaters included—happy and quiet.
Ready? Let’s cook!
Why You’ll Love It
- Delivers bold flavor: creamy, cheesy gratin with caramelized sprouts.
- Balances richness: crisp-topped veggies alongside juicy, herb-basted steak.
- Streamlines cooking: oven and stovetop timing overlap efficiently.
- Adapts easily: swap cheeses, add bacon, or adjust doneness.
- Feels special yet simple: weeknight-friendly, dinner-party worthy.
Ingredients
- 680 g Brussels sprouts, halved — choose similarly sized for even roasting
- 2 tbsp olive oil — for roasting sprouts
- 1 tsp kosher salt, divided — season in layers
- 0.5 tsp black pepper, divided — freshly ground if possible
- 1 tbsp unsalted butter — for sautéing aromatics
- 1 small yellow onion, finely diced — sweet, not sharp
- 2 cloves garlic, minced — fresh, not jarred
- 240 ml heavy cream — full-fat for best texture
- 120 ml whole milk — balances richness
- 1 tsp Dijon mustard — adds subtle tang
- 0.25 tsp nutmeg, freshly grated — warms the sauce
- 75 g Gruyère cheese, shredded — melts creamy and nutty
- 50 g Parmesan cheese, grated — split for sauce and topping
- 0.5 cup panko breadcrumbs — extra crunch
- 1 tbsp olive oil — to moisten breadcrumbs
- 680 g ribeye or New York strip steak, 1–1.25 in thick — well-marbled cut
- 1 tbsp neutral high-heat oil — canola or grapeseed
- 1 tsp fresh thyme leaves, chopped — earthy aroma
- 1 tsp fresh rosemary, chopped — piney, robust
- 1 tbsp unsalted butter — for basting steak
- 1 tsp flaky sea salt, optional — finish for texture and pop
Step-by-Step Method
Preheat The Oven
Heat the oven to 425°F (220°C). Position a rack in the center. Lightly grease a large oven-safe skillet or a 9×13 baking dish. Prepare all ingredients: trim and halve Brussels sprouts, dice onion, mince garlic, shred cheeses, and measure liquids. Pat the steak dry and set it aside. This mise en place speeds cooking and guarantees even roasting and searing.
Roast The Brussels Sprouts
Toss sprouts with 2 tablespoons olive oil, 0.5 teaspoon kosher salt, and 0.25 teaspoon black pepper. Spread cut-side down in the skillet or baking dish. Roast 15–18 minutes until edges are browned and centers are just tender. Reduce oven temperature to 400°F (205°C). Keep sprouts in the dish; they’ll be sauced and baked next.
Season The Steak
Season both sides of the steak with the remaining 0.5 teaspoon kosher salt and 0.25 teaspoon black pepper. Let it rest at room temperature for 15 minutes. This helps even cooking and better crust formation. Pat dry again if moisture appears. Meanwhile, start the sauce so it’s ready when the sprouts finish roasting.
Sweat The Aromatics
Melt 1 tablespoon butter in a medium saucepan over medium heat. Add the finely diced onion. Cook 3–4 minutes, stirring, until translucent and softened without browning. Stir in minced garlic and cook 30 seconds until fragrant. Maintain moderate heat to avoid scorching the garlic, which can turn bitter.
Simmer The Cream Sauce
Whisk in heavy cream, whole milk, Dijon mustard, and freshly grated nutmeg. Bring to a gentle simmer for 2–3 minutes, stirring to prevent scorching. Remove from heat. The goal is a lightly thickened, cohesive base. Season lightly if needed, keeping in mind the cheeses and gratin will add saltiness.
Melt The Cheeses
Off heat, stir in shredded Gruyère and half the grated Parmesan until fully melted and smooth. Whisk to emulsify. The sauce should be glossy and pourable. If overly thick, loosen with a splash of milk. If stringy, warm gently while whisking. Taste and adjust seasoning, keeping balance with the roasted sprouts.
Mix The Breadcrumb Topping
In a small bowl, combine panko breadcrumbs with 1 tablespoon olive oil and the remaining Parmesan. Toss to evenly coat. The oil helps promote crisp, golden topping. Season lightly with a pinch of salt if desired. For extra crunch, briefly toast the mixture in a dry skillet until just golden.
Assemble & Bake The Gratin
Pour the hot cheese sauce evenly over the roasted Brussels sprouts. Spread to coat, keeping sprouts mostly submerged. Sprinkle the panko-Parmesan mixture evenly on top. Return to the oven at 400°F (205°C). Bake 12–15 minutes until bubbling at the edges and the topping is deeply golden and crisp.
Sear & Baste The Steak
Heat a large skillet over medium-high until just smoking. Add 1 tablespoon neutral oil. Sear steak 2–3 minutes per side until deeply browned. Add 1 tablespoon butter, thyme, and rosemary. Tilt the pan and baste 30–60 seconds per side. For doneness, use an instant-read thermometer and pull 5°F before target.
Rest & Slice The Steak
Transfer steak to a cutting board. Tent loosely with foil and rest 5 minutes to retain juices. Slice against the grain into 0.5-inch slices. Sprinkle with flaky sea salt if using. Resting stabilizes juices and guarantees tenderness and flavor in every bite. Keep warm while the gratin sets briefly.
Finish The Gratin
Remove the gratin from the oven and let stand 5 minutes to set. The sauce will thicken slightly as it cools, improving sliceability. Optionally finish with a pinch of flaky sea salt for added texture and pop. Check the topping for desired color; broil briefly if needed, watching closely.
Plate & Serve
Spoon generous portions of Brussels sprouts gratin onto plates. Arrange sliced steak alongside or drape over the gratin to mingle juices with the creamy sauce. Garnish with extra thyme leaves if desired. Serve immediately while hot and crisp. Enjoy the contrast of caramelized sprouts, velvety sauce, and juicy steak.
Ingredient Swaps
- Cheese: Swap Gruyère with Swiss, fontina, or mozzarella (milder/budget); use sharp cheddar for a bolder, cheaper option; Parmesan → Pecorino Romano.
- Dairy: Replace heavy cream/milk with half-and-half; for lighter, use evaporated milk; for dairy-free, use full-fat coconut milk or oat cream and vegan cheeses.
- Breadcrumbs: Use crushed Ritz/saltines, regular breadcrumbs, or gluten-free panko; for low-carb, use crushed pork rinds or toasted almond meal.
- Aromatics: Yellow onion → shallot or leek; fresh garlic → 1/2 tsp garlic powder.
- Mustard: Dijon → whole-grain or 1/2 tsp yellow mustard + pinch sugar.
- Spices/Herbs: Nutmeg → a pinch of allspice or none; thyme/rosemary → Italian seasoning or dried thyme (1/3 quantity of fresh).
- Steak: Ribeye/NY strip → sirloin, flat iron, or hanger; for budget, top round seared then finished in oven; for non-beef, use pork chops or chicken thighs.
- Oils: Neutral high-heat oil → canola, grapeseed, avocado; olive oil → any neutral oil or melted butter.
- Brussels sprouts: Use halved baby cabbages or shredded green cabbage (shorter roast), or mix with cauliflower/broccoli.
You Must Know
Doneness • If your steak is thicker than 1.25 inches, finish it in a 400°F oven on a sheet pan to target center temps: pull at 120°F (rare), 125–130°F (medium-rare), 135°F (medium). Why: thicker cuts brown outside before the center warms; oven finish evens heat.
Visual: bead of rosy juices on slice = medium-rare.
Troubleshoot • If the gratin looks pale but sprouts are tender, move it to the top rack and switch to broil for 45–90 seconds until the panko is deep golden. Why: high top heat crisps the topping without overcooking the interior.
Anchor: panko turns amber and smells toasty.
Scale • For 6–8 servings, multiply all gratin ingredients by 1.5 and use a 9×13 plus an extra small dish; cook time increases by 5–8 minutes until bubbling at edges.
For steak, plan 8–10 oz cooked per person. Why: surface area and depth change heat penetration.
Flavor Boost • For nuttier depth, toast the nutmeg in the hot cream for 30 seconds, and add 1 teaspoon Worcestershire to the sauce.
Finish steak slices with 0.5 teaspoon lemon juice right before serving. Why: acid and umami lift richness.
Sensory: sauce should smell savory-sweet, not flat.
Make-Ahead • To get ahead, assemble the gratin through cheese sauce and topping, chill covered up to 24 hours, then cook from cold adding 10–12 minutes until center is visibly bubbling.
Why: cold start slows heating; bubbling indicates full melt and set.
Serving Tips
- Slice steak over gratin, drizzle pan jus, finish with flaky sea salt.
- Add brightness with lemon zest and chopped parsley over the gratin.
- Serve with a crisp green salad and a light vinaigrette.
- Pair with medium-bodied red wine, like Pinot Noir or Merlot.
- Plate with roasted carrots or mashed potatoes for a heartier spread.
Storage & Make-Ahead
Refrigerate leftovers in an airtight container for 3–4 days.
Reheat covered at 350°F until hot.
Assemble gratin up to 24 hours ahead (hold breadcrumbs separately).
Then bake fresh.
Steak is best cooked day-of.
Slice just before serving.
Gratin freezes well up to 2 months.
Thaw overnight, reheat covered, then uncover to crisp.
Reheating
Reheat gently: cover gratin and steak separately.
Oven 325°F, 10–15 minutes, covered.
Microwave low power in short bursts, covered.
Stovetop low heat with splash of cream or broth; avoid overcooking steak.
Steakhouse Date-Night Staple
How do you bring that dimly lit, linen-napkin magic home without a reservation? I set the mood with soft lighting, a favorite playlist, and this duo: a bronzed ribeye and a bubbling Brussels sprouts gratin. It’s the steakhouse rhythm, streamlined.
I pat the steak dry, season confidently, and sear in a ripping-hot pan until a mahogany crust forms. Butter, thyme, and rosemary hit the heat—then I baste, fast and fragrant.
While the steak rests under foil, the gratin finishes, edges sizzling, panko crackling over a silk-smooth Gruyère sauce. I slice the steak into thick ribbons, pink at the heart, and nestle them beside that golden casserole. A kiss of flaky salt, warm plates, and a glass of red—date night, perfectly done at home.
Final Thoughts
Give this cozy Brussels sprouts gratin with seared steak a try—you’ll get crisp, creamy, and savory all on one plate.
Feel free to tweak the cheeses or add bacon to make it your own!
Frequently Asked Questions
Can I Make This Entirely Dairy-Free Without Sacrificing Creaminess?
Yes—you can. I’d use coconut cream and oat milk, thicken with a cornstarch slurry, whisk in Dijon, nutritional yeast, and a splash of miso. Finish with olive-oil panko. It’s silky, savory, and beautifully golden.
What Wine Pairs Best With the Gratin and Steak?
Choose a bold, structured red: I’d pour Cabernet Sauvignon or Bordeaux for the steak’s sear and Gruyère’s richness. Prefer freshness? I’d pick Barolo or Brunello. For a plush, spicy hug, I’d open Syrah/Shiraz.
How Do I Scale the Recipe for Eight Guests?
Double every ingredient for eight guests; use two pans to avoid crowding. Roast sprouts on two racks, rotate halfway. Sear steaks in batches, rest well. I’ll keep seasoning proportional and taste the sauce—silky, bubbling, golden, then serve.
Can I Cook the Steak Sous Vide Before Searing?
Yes—you can sous vide, then sear. I’d bag with thyme and rosemary, cook 129°F for medium-rare, dry aggressively, sear in ripping-hot oil, baste with butter, rest briefly. Time it so gratin finishes bubbling.
What’s the Best Way to Use Frozen Brussels Sprouts Here?
Thaw them fully, pat very dry, then roast cut-side down on a preheated, oiled sheet until edges caramelize. I’ll keep seasoning bold, reduce initial roast time, and rely on the bubbling gratin to restore tenderness and richness.
Brussels Sprouts Gratin with Steak
Equipment
- 1 large oven-safe skillet or 1 baking dish (9×13)
- 1 large skillet for steak if not using oven-safe
- 1 Medium saucepan
- 1 Mixing bowl
- 1 Cutting board
- 1 Chef's knife
- 1 Whisk
- 1 Tongs
- 1 Measuring cups set
- 1 Measuring spoons set
- 1 sheet pan optional for finishing steak
- 1 aluminum foil sheet
Ingredients
- 1 1/2 pound Brussels sprouts trimmed and halved
- 2 tablespoon olive oil
- 1 teaspoon kosher salt divided
- 1/2 teaspoon black pepper divided
- 1 tablespoon unsalted butter
- 1 small yellow onion finely diced
- 2 clove garlic minced
- 1 cup heavy cream
- 1/2 cup whole milk
- 1 teaspoon Dijon mustard
- 1/4 teaspoon nutmeg freshly grated
- 3/4 cup Gruyère cheese shredded
- 1/2 cup Parmesan cheese grated
- 1/2 cup panko breadcrumbs
- 1 tablespoon olive oil for breadcrumbs
- 1 1/2 pound ribeye or New York strip steak 1–1 1/4 inches thick
- 1 tablespoon neutral high-heat oil
- 1 teaspoon fresh thyme leaves chopped
- 1 teaspoon fresh rosemary chopped
- 1 tablespoon unsalted butter for basting
- 1 teaspoon flaky sea salt for finishing, optional
Instructions
- Preheat the oven to 425°F (220°C).
- Toss Brussels sprouts with 2 tablespoons olive oil, 1/2 teaspoon kosher salt, and 1/4 teaspoon black pepper, then spread cut-side down in a large oven-safe skillet or baking dish.
- Roast Brussels sprouts for 15–18 minutes until edges are browned and centers are just tender, then reduce oven to 400°F (205°C).
- Meanwhile, season steak on both sides with remaining 1/2 teaspoon kosher salt and 1/4 teaspoon black pepper and let sit at room temperature for 15 minutes.
- In a saucepan over medium heat, melt 1 tablespoon butter, add diced onion, and cook 3–4 minutes until translucent.
- Stir in garlic and cook 30 seconds until fragrant.
- Whisk in heavy cream, milk, Dijon, and nutmeg, bring to a gentle simmer for 2–3 minutes, and remove from heat.
- Stir Gruyère and half the Parmesan into the hot cream until melted and smooth.
- In a bowl, mix panko with 1 tablespoon olive oil and the remaining Parmesan.
- Pour cheese sauce over roasted Brussels sprouts, top evenly with panko mixture, and return to the oven at 400°F for 12–15 minutes until bubbling and golden.
- While gratin bakes, heat a large skillet over medium-high until just smoking, add neutral oil, and sear steak 2–3 minutes per side until deep brown.
- Add butter, thyme, and rosemary to the skillet and baste steak for 30–60 seconds per side, then transfer to a cutting board to rest for 5 minutes.
- Tent steak loosely with foil while resting and slice against the grain into 1/2-inch slices.
- Remove gratin from oven and let stand 5 minutes to set, then season with flaky sea salt if using.
- Serve sliced steak alongside or over portions of Brussels sprouts gratin.
Notes
