In a large skillet over medium heat, add a drizzle of oil. Toss in the diced onion and green pepper, cooking until soft (around 5 minutes). Then add the sliced mushrooms and continue to sauté until they are tender and fragrant.

Push the vegetables to the side of the skillet and add the ground beef in the center. Use a spatula to break it up and cook until browned, roughly 5-7 minutes. Make sure to season with salt and pepper to taste.

Once the beef is browned, mix in the sautéed veggies. Pour in the beef broth and stir in the Worcestershire sauce, allowing the mixture to simmer for 3-5 minutes until it begins to thicken.

Stir in the shredded provolone cheese until it melts into the mixture.

Spoon the cheesy meat mixture onto the sandwich rolls while it’s still hot. Serve immediately.