1 lb. ground beef
1 (14-oz) jar pizza sauce
1 large green pepper
1 medium onion
1 (8-oz) package baby bella mushrooms
2 cups shredded mozzarella cheese
Dice green pepper, onion and mushrooms.
Add veggies and ground beef to pan. Cook until ground beef is browned and veggies are tender. Drain.
In crock pot, layer ground beef and veggie mixture, sauce, cheese and pepperoni. Repeat layers.
Cook on low in crock pot for 2 hours, until cheese is melted and and casserole is heated through.