Garlic Butter Brussels Sprouts Steak Casserole

Picture glossy Brussels sprouts, emerald edges caramelized to mahogany, nestled among seared steak cubes that glisten in garlic butter.

Imagine the nutty aroma mingling with a smoky whisper of paprika as steam curls up, and Parmesan melts into a silky, savory sheen—comfort you can smell before the first bite.

This casserole matters to me because it turns simple, affordable ingredients into a cozy, restaurant-worthy dinner without demanding an entire evening.

It’s the kind of recipe that respects your time and rewards your senses.

On busy weeknights, it’s hands-off once the skillet hits the oven; for Sunday suppers, it anchors the table with substance and warmth.

I first made it after a late soccer practice, when everyone was hungry and patience was thin—fifteen minutes later, the kitchen quieted to the sound of satisfied forks.

It’s versatile, forgiving, and unapologetically delicious. Ready? Let’s cook!

Why You’ll Love It

• Delivers bold, garlicky, buttery flavor in every bite
• Cooks fast in one skillet for easy cleanup
• Achieves steakhouse sear and caramelized Brussels sprouts
• Flexible add-ins: mushrooms, bacon, or cheesy broiled topping
• Finishes bright with lemon and fresh parsley

Ingredients

• 1.5 lb sirloin steak, 1-inch cubes — well-marbled for tenderness (choose bright, firm beef)
• 1 lb Brussels sprouts, trimmed and halved — similar size for even cooking (pick tightly packed heads)
• 3 tbsp unsalted butter, divided — for searing and finishing (use high-fat European style if available)
• 1 tbsp olive oil — helps butter resist burning (use a robust extra-virgin)
• 4 cloves garlic, minced — aromatic base (choose firm, fresh cloves)
• 1 tsp kosher salt, divided — seasons in layers (use Diamond Crystal if possible)
• 1/2 tsp black pepper, divided — freshly ground for best flavor (medium grind)
• 1/2 tsp smoked paprika — adds subtle smokiness (Spanish pimentón preferred)
• 1/2 tsp onion powder — boosts savory depth (no anti-caking if possible)
• 1/4 tsp crushed red pepper flakes, optional — gentle heat (adjust to taste)
• 1/2 cup low-sodium beef broth — deglazing and moisture (avoid over-salting)
• 1 tbsp Worcestershire sauce — umami lift (shake before using)
• 1 tsp Dijon mustard — emulsifies and brightens (smooth, not whole-grain)
• 1/4 cup grated Parmesan cheese — nutty finish (grate from a wedge)
• 1 tbsp fresh lemon juice — balances richness (juice just before serving)
• 2 tbsp fresh parsley, chopped — fresh herb pop (flat-leaf for best texture)

Step-by-Step Method

Sear the Steak

Preheat oven to 400°F. Pat steak cubes dry. Season with half the salt and pepper, plus smoked paprika and onion powder.

Heat skillet over medium-high. Add olive oil and 1 tablespoon butter. Sear steak in a single layer, 1–2 minutes per side, until browned but still rare inside. Work in batches. Transfer to a bowl with juices.

Caramelize the Brussels Sprouts

Add 1 tablespoon butter to the same hot skillet. Place Brussels sprouts cut side down in a single layer. Season with remaining salt and pepper.

Sear without moving for 3–4 minutes until deeply caramelized. Keep heat high for color. Avoid overcrowding; work in batches if necessary for even browning.

Bloom Garlic and Spice

Stir in minced garlic and crushed red pepper flakes.

Cook 30 seconds, stirring, until fragrant and just golden at the edges. Don’t burn the garlic. Adjust heat slightly if needed to prevent scorching. Keep Brussels sprouts moving lightly to distribute the aromatics and coat with the garlicky butter.

Deglaze and Build the Sauce

Pour in beef broth to deglaze, scraping up browned bits with a wooden spoon.

Stir in Worcestershire sauce and Dijon mustard until emulsified and glossy. Simmer briefly to reduce slightly. Taste the liquid and adjust seasoning if needed, especially if broth isn’t low-sodium.

Reunite and Butter-Baste

Return seared steak and any accumulated juices to the skillet. Toss gently to coat steak and Brussels sprouts in the pan sauce.

Dot the top evenly with the remaining 1 tablespoon butter. Make certain contents are distributed in an even layer for consistent roasting in the oven.

Roast to Finish

Transfer skillet to the preheated oven. Bake 8–10 minutes until Brussels sprouts are tender and steak reaches medium to medium-rare.

Check doneness at 8 minutes for lean cuts. Pull slightly early to account for carryover cooking. Avoid overcooking to keep steak juicy and sprouts vibrant.

Rest and Cheese

Remove skillet from oven. Sprinkle grated Parmesan evenly over the hot casserole.

Tent loosely with foil and let rest for 5 minutes. Allow juices to redistribute and cheese to soften. This brief rest enhances tenderness and melds flavors before the final bright finishing touches.

Brighten and Serve

Uncover and finish with fresh lemon juice and chopped parsley. Toss gently to coat without breaking up sprouts.

Taste and adjust salt or pepper if needed. Serve hot straight from the skillet. Pair with crusty bread or mashed potatoes to capture the garlicky, buttery pan juices.

Ingredient Swaps

• Steak: swap with boneless chicken thighs, pork tenderloin cubes, or firm tofu/tempeh for a vegetarian option. For budget, use chuck steak or sirloin tip and slice thinner.
• Brussels sprouts: use broccoli florets, green beans, or halved baby cabbage; frozen Brussels sprouts work if thawed and well-dried.
• Butter: replace with ghee or olive oil; for dairy-free, use plant butter.
• Beef broth: substitute chicken or vegetable broth; add a splash of soy sauce or coconut aminos for depth if veg.
• Worcestershire: use soy sauce + a splash of vinegar; for vegetarian, make certain a fish-free brand or use coconut aminos.
• Parmesan: swap with Pecorino, shredded Gruyère, or a dairy-free Parmesan.
• Dijon: use whole-grain mustard or a smaller amount of yellow mustard.
• Spices: smoked paprika → regular paprika + a pinch of cumin; red pepper flakes → cayenne to taste.
• Lemon juice: substitute with red or white wine vinegar.

You Must Know

– Doneness • If steak looks browned outside but you’re unsure inside, check a center cube with an instant-read thermometer; pull at 125–130°F for medium-rare knowing carryover adds ~5°F during the 5-minute rest.

Color cue: rosy center, juices lightly pink, not red.

– Troubleshoot • When sprouts are still firm after the oven time, splash in 2–3 tablespoons hot broth, cover tightly with foil, and return to heat for 3–5 minutes; steam speeds softening without overcooking steak.

Visual cue: knife slips in with slight resistance.

– Flavor Boost • For deeper umami, add 1 teaspoon soy sauce and 1/2 teaspoon fish sauce with the Worcestershire; balances the lemon and Parmesan.

Taste at the end—aim for savory but not salty; adjust with 1–2 teaspoons water if needed.

– Scale • For 6–8 servings, double ingredients but divide into two 12-inch pans so surfaces aren’t crowded; target the same oven time, rotating pans at the halfway point.

Visual cue: sprouts have dark caramel edges, not pale green.

– Make-Ahead • To get ahead by 1 day, cube and dry the steak, trim/halve sprouts, and pre-measure seasonings; store steak uncovered on a rack in the fridge 8–24 hours to dry the surface.

Why: better browning in 1–2 minutes per side, less purge in the pan.

Serving Tips

• Serve over creamy mashed potatoes or cauliflower mash to catch the garlic-butter juices.
• Pair with a crisp green salad and lemon vinaigrette to balance richness.
• Add crusty sourdough or garlic bread for dipping and texture.
• Pour a medium-bodied red wine, like Merlot or Syrah, alongside.
• Plate in a warm skillet, finish with extra parsley and lemon zest for brightness.

Storage & Make-Ahead

Cool completely, then refrigerate in an airtight container 3–4 days.

For make-ahead, sear components and assemble up to 24 hours ahead; bake just before serving.

Reheat gently at 300°F until warmed through, or microwave in bursts.

Freezing isn’t ideal (Brussels sprouts soften), but acceptable up to 2 months.

Reheating

Reheat gently.

Microwave covered on 50% power, stirring once.

Oven at 325°F, covered, 12–15 minutes.

Or stovetop low with splash of broth and butter, stirring occasionally until warmed through.

Weeknight Potluck Favorite

Leftovers reheat like a dream, but I love making this Garlic Butter Brussels Sprouts Steak Casserole fresh when I’m headed to a weeknight potluck—it travels well, smells irresistible, and serves itself straight from the skillet.

I sear the steak and caramelize the sprouts, slide the skillet into the oven, then tent it for the drive. When I walk in, that garlicky butter aroma gets everyone hovering.

It’s hearty enough to stand alone, but I park it beside a simple green salad or warm rolls. Want it extra crowd-pleasing? Shower on Parmesan right before serving and finish with lemon for brightness.

The 12-inch skillet keeps heat beautifully, so each scoop stays juicy, glossy, and sizzling. Expect clean plates and second helpings.

Final Thoughts

Ready to dig in? Give this Garlic Butter Brussels Sprouts Steak Casserole a try tonight, and feel free to tweak it—add mushrooms, swap in bacon, or finish with a bubbly Gruyère broil to make it your own!

Frequently Asked Questions

Can I Make This Casserole Dairy-Free Without Losing Flavor?

Yes—you can. I swap ghee or vegan butter, use coconut aminos and Dijon, and finish with lemon. Nutritional yeast replaces Parmesan, olive oil boosts richness, and a garlic-thyme sizzle keeps everything savory, caramelized, and deeply satisfying.

What Wine Pairs Best With This Casserole?

I’d pour a medium-bodied red like Rioja or Pinot Noir. You’ll taste cherry, earth, and gentle spice hugging the savory sear and garlic. Prefer white? I’d choose oaked Chardonnay—creamy texture, citrus, and toast balance everything beautifully.

How Do I Scale the Recipe for Eight Servings?

Double everything for eight servings: ingredients, seasoning, and liquids. I’d use two large skillets or sear in batches, then bake in a bigger dish. Keep oven time similar, check doneness, rest, finish, and serve steaming.

Is This Recipe Suitable for Keto or Low-Carb Diets?

Yes—it’s keto-friendly and low-carb. I savor rich butter, seared steak, and Brussels sprouts without starchy fillers. I’d skip extra sugary sauces, watch portions, and enjoy that garlicky sizzle while keeping net carbs comfortably low for you.

Can I Cook It Entirely on the Stovetop Without Baking?

Yes—you can. I’d sear the steak, caramelize sprouts, add garlic, deglaze, then simmer covered on medium-low until tender. Uncover to reduce, finish with butter, Parmesan, lemon, and parsley. You’ll get glossy, garlicky, pan-kissed perfection.