Preheat oven to 350 degrees F.
Cut tops off peppers; remove seeds and membranes. Chop edible part of tops and set aside. Cut off a little bit of the bottom of each pepper so it can stand flat, making sure you do not make any holes.
Meanwhile, cook meat over medium-high heat. Drain off fat and set aside.
Heat olive oil in a large skillet over medium heat until hot. Sauté chopped green pepper (from tops) and chopped onion for about 5 minutes, or until vegetables are tender. Add diced tomatoes, tomato sauce, garlic, salt, and pepper. Simmer for 5 minutes. Add rice and stir until coated with mixture. Remove from heat and set aside.
In a large mixing bowl, combine egg and Ricotta cheese. Add oregano, Italian seasoning, red pepper flakes and Worcestershire sauce. Gently stir to blend. Add drained ground beef to the Ricotta mixture and stir to combine. Add the tomato mixture and 1/2 cup Cheddar cheese. Mix well. Adjust seasonings as needed.
Stuff peppers to the top with the meat mixture and place in a 9x13" pan. Bake for 35-40 minutes. If desired, top stuffed peppers with additional shredded Cheddar cheese 5 minutes before peppers are done; bake until cheese is melted.
by The Savvy Kitchen