Preheat your oven to 375°F (190°C).
In a large skillet, prepare the flank steak over medium-high heat until browned.
Add onions, bell peppers, and mushrooms to the skillet, cooking until softened.
Stir in the garlic and cook for another minute until fragrant.
Pour in the beef broth, Worcestershire sauce, and Italian seasoning; simmer for a few minutes.
Toss the cooked pasta into the mixture until well combined, then transfer to a greased baking dish.
Top the mixture with provolone and Parmesan cheese equally across the surface.
Bake for 25-30 minutes until the cheese is melted and bubbly.
Let it cool for a few minutes before serving; this allows the casserole to set slightly.
