Chop reserved green bell pepper tops and measure out 1/4 cup.
Bring a pot of water to a boil; cook whole green bell peppers until slightly tender, about 5 minutes. Drain and season inside of bell peppers with a little salt.
Heat a large skillet over medium-high heat. Cook and stir beef, onion, garlic, and reserved 1/4 cup chopped green bell pepper in the hot skillet until ground beef is browned and crumbly, 5 to 7 minutes; drain and discard grease.
Preheat oven to 350 degrees F (175 degrees C).
Stir canned tomatoes and liquid, rice, 1/2 cup water, Worcestershire sauce, 1 teaspoon salt, hot sauce, and black pepper into ground beef mixture; bring to a boil. Reduce heat, cover skillet with a lid, and simmer until rice is tender, 15 to 18 minutes.
Stir 3/4 the mozzarella cheese and 3/4 the tomato sauce into ground beef-rice mixture. Stuff bell peppers with ground beef-rice mixture; top each with remaining mozzarella cheese and tomato sauce. Arrange stuffed peppers in a baking dish. Cover dish with aluminum foil.
Bake in the preheated oven until cooked through and cheese is melted, 30 to 35 minutes.
