Philly cheese stuffed peppers

1 lb Thinly Sliced Sirloin Steak
8 Slices Provolone Cheese
4 Lrg Green Bell Peppers
1 Med Sweet Onion
1 lb White Mushrooms
3 Tbsp Butter
3 Tbs. Olive Oil
Salt and Pepper – to taste
DIRECTIONS
Slice a thin piece off each pepper lengthwise remove insides.
Slice onions and mushrooms. Saute over medium heat with butter, olive oil. Saute until onions caramelized. About 25-30 minutes. Salt and pepper the steak and saute in a little olive oil until not pink
Preheat oven to 400* Line the inside of pepper with a slice of cheese. Fill pepper with meat mix.
Top each pepper with another slice of cheese. Bake for 15-20 min