Fill a large pot up with water and bring to a boil. Add peppers and continue boiling for 5 minutes. Drain peppers, rinse with cold water and place them standing up in a 11x8 baking dish.
Add ground beef, chopped onions and garlic in a large skillet and cook over medium high heat until beef is browned and cooked. Drain meat to remove excess fat. Season with salt and pepper to taste.
Add diced tomatoes, beef broth, uncooked rice and Worcestershire sauce to skillet and mix. Bring to a boil, and then reduce to a simmer, cover and cook for 15 minutes, or until rice is tender.
Fill peppers up with ground beef mixture. The peppers should be close to completely filled.
In a medium sized bowl mix tomato soup and water together. Pour this mixture over the peppers.
Cover peppers with aluminum foil and bake for 25 minutes. Remove foil, sprinkle mozzarella cheese on peppers and bake for 10 more minutes, uncovered.
Remove from oven, allow to cool for a few minutes and serve. Enjoy!