Cheesesteak

4 hoagie rolls, sliced

1/2 green pepper, sliced

1 large white onion, cut in half and sliced thick

8 oz mushrooms, sliced

1.25 to 1.5 pounds beef ribeye steaks (sliced thinly across the grain and then chopped roughly again so they are small pieces)

salt & pepper

3 1/2 Tablespoons salted butter

8 slices of cheese (Provolone or Muenster)