Bring a large pot of salted water to a boil and cook the penne until al dente according to package directions, reserving 1/2 cup pasta water before draining.

Pat the steak strips dry and season with 1/2 teaspoon kosher salt, 1/4 teaspoon black pepper, garlic powder, and Italian seasoning.

Heat 1 tablespoon olive oil in a large skillet over medium-high heat and sear the steak strips in a single layer for 2 to 3 minutes until browned but still medium inside, then transfer to a plate.

Reduce heat to medium, add the remaining 1 tablespoon olive oil and the butter to the skillet, and sauté the red onion for 2 minutes until softened.

Stir in the minced garlic and cook for 30 seconds until fragrant.

Add bell pepper, zucchini, yellow squash, and broccoli and cook for 4 to 5 minutes until crisp-tender, stirring occasionally.

Add cherry tomatoes and red pepper flakes and cook for 1 minute until tomatoes just begin to soften.

Return the steak and any juices to the pan, add the drained pasta, and toss to combine.

Pour in 1/4 to 1/2 cup reserved pasta water and the lemon juice, season with remaining 1/2 teaspoon kosher salt and 1/4 teaspoon black pepper, and toss until glossy.

Remove from heat, sprinkle with Parmesan and basil, and toss once more to coat evenly.

Let rest for 5 minutes to allow flavors to meld before serving.