Slice a thin piece off each pepper lengthwise, remove ribs and seeds.Slice onions and mushrooms.
Saute over medium heat with butter, olive oil, and a little salt and pepper.
Saute until onions and mushroom are nice and caramelized.
About 25-30 minutes.
Salt and pepper the steak and saute in a little olive oil until just not pink.
About 5 minutes.Preheat oven to 400*Add steak to the onion/mushroom mixture and stir to combine.Line the inside of each pepper with a slice of provolone cheese.Fill each pepper with meat mixture until they are overflowing.Top each pepper with another slice of provolone cheese.Bake for 15-20 minutes until the cheese on top is golden brown