1. Slice peppers in half lengthwise and clean out the inside to make a nice bowl 2. In a large pan, heat oil over low-medium heat. When oil is heated, add mushrooms, onions, garlic and pepper. Sauté until onions and mushroom are nice and caramelized. About 20-30 minutes. 3. Preheat oven to 400° 4. Slice roast beef into thin strips and add to the onion/mushroom mixture. I found that using tongs to “toss” the mixture together was easier than trying to stir with a spoon. Allow to cook 5-10 minutes. 5. Line the inside of each pepper half with a slice of provolone cheese. Fill each with the meat mixture until they are nearly overflowing. Then, top each pepper with another slice of provolone cheese. 6. Bake for 15-20 minutes until the cheese on top is golden brown.