1. Preheat your oven to 350°F (175°C).
2. In a skillet over medium heat, add olive oil and sauté the onions, peppers, and mushrooms until they are tender, about 5-7 minutes.
3. Add the thinly sliced ribeye to the skillet, seasoning with garlic powder, onion powder, salt, and pepper. Cook until the meat is browned, approximately 5 minutes.
4. In a large baking dish, place the torn hoagie roll pieces evenly across the bottom.
5. Layer the sautéed meat and vegetables over the bread pieces.
6. Pour the beef broth evenly over the top to keep everything moist and flavorful.
7. Sprinkle the shredded provolone cheese over the entire dish.
8. Drizzle the melted butter over the top of the casserole to give it a rich finish.
9. Bake in the preheated oven for 20-25 minutes, or until the cheese is bubbly and golden brown.
10. Allow the casserole to cool slightly before serving to let the flavors meld together.

Remember, patience is key. Letting it rest helps bring out the best flavors, much like how Mama Lou always let her dishes sit before serving.