Heat olive oil in a large skillet over medium-high heat. Sauté onions and green bell peppers for 3-5 minutes until tender. If using mushrooms, add after 3 minutes.

Push vegetables aside and add ground beef to the center of the skillet. Cook for 5-7 minutes until browned.

Stir in garlic powder, Worcestershire sauce, salt, and black pepper. Cook for an additional 2 minutes.

Reduce heat to low, arrange provolone cheese over the mixture, cover, and cook for 2-3 minutes until melted.

Slice hoagie rolls lengthwise to create pockets. Optionally toast in the oven.

Spoon the beef and vegetable mixture into each hoagie roll and pack generously.

Serve hot, pairing with crispy fries or a fresh salad.