Step 1: Preheat your oven to 350°F (175°C).
Step 2: In a large skillet over medium-high heat, add 1 tablespoon of olive oil. Once hot, add the thinly sliced steak and season with salt and pepper. Cook until browned, about 3-5 minutes. Remove the steak from the skillet and set aside.
Step 3: In the same skillet, add the remaining 1 tablespoon of olive oil. Add the sliced onion and bell pepper, and sauté until softened, about 5 minutes. Stir in the minced garlic and cook for an additional minute until fragrant.
Step 4: In a large mixing bowl, combine the cooked pasta (or diced potatoes), sautéed vegetables, cooked steak, beef broth, and Worcestershire sauce. Mix everything well to ensure all ingredients are evenly distributed.
Step 5: Transfer the mixture to a greased 9x13 inch baking dish. Spread the mixture evenly and then top generously with the shredded provolone cheese, covering the entire surface.
Step 6: Cover the baking dish with aluminum foil and bake in the preheated oven for 20 minutes. After 20 minutes, remove the foil and continue to bake for an additional 10-15 minutes, or until the cheese is bubbly, melted, and golden brown.
Step 7: Remove the casserole from the oven and let it cool for about 5 minutes before serving. This brief resting period helps the casserole set, making it easier to serve.