Tater Tot Pizza Casserole

1 lb. ground beef
1/4 cup chopped onion
1 (10-3/4 oz.) cream of mushroom soup
1 (8 oz.) can pizza sauce
2 oz. sliced pepperoni
1/2 cup chopped green bell pepper
1 cup shredded mozzarella cheese
1 (16-oz.) pkg. frozen tater tots

Heat oven to 375 degrees. Spray 8-inch square glass baking dish with non-stick cooking spray. In large skillet, cook ground beef and onion over medium-high heat until beef is thoroughly cooked, stirring frequently. Drain. Reduce heat to medium; stir in soup. Cook until mixture comes to a boil, stirring occasionally. Spoon beef mixture into sprayed baking dish. Spoon pizza sauce evenly over top. Arrange pepperoni and bell pepper over sauce. Sprinkle with cheese. Arrange tater tots over cheese. Cover with foil. Bake at 375 degrees for 30 minutes. Remove foil; bake an additional 15 to 20 minutes or until thoroughly heated. Enjoy!