01 - Preheat oven to 375°F. Arrange bell pepper halves cut side up in a baking dish.
02 - Heat 1 tablespoon of olive oil in a large skillet over medium-high heat. Sauté onions and mushrooms until softened and lightly browned, about 5 to 7 minutes. Add minced garlic and cook for an additional 1 minute. Remove the mixture from skillet and set aside.
03 - Add remaining tablespoon of olive oil to the skillet. Cook seasoned sliced beef with salt and pepper until just browned, approximately 3 to 4 minutes. Stir in Worcestershire sauce, return the onion and mushroom mixture to the pan, combine thoroughly, then remove from heat.
04 - Place one slice of provolone cheese at the bottom of each bell pepper half. Fill peppers evenly with beef mixture.
05 - Place a second slice of provolone cheese atop each stuffed pepper.
06 - Cover the baking dish with foil and bake for 25 minutes. Remove foil and bake an additional 5 to 10 minutes until cheese bubbles and peppers are tender.
07 - Allow stuffed peppers to cool for 5 minutes before serving.