Stuffed Peppers with Ground Beef and Rice

Cut tops off peppers; remove seeds and membranes. Chop edible part of tops and set aside. Rinse peppers under cold water. Place peppers in a large pot; cover with salted water. Bring to a boil; reduce heat, cover, and simmer for 5 minutes. Drain peppers and set aside.
Heat olive oil and butter in a large skillet over medium heat until hot. Sauté chopped green pepper (from tops), chopped onion, and chopped celery for about 5 minutes, or until vegetables are tender. Add tomatoes, tomato sauce, crushed garlic, oregano, basil, 1 teaspoon salt, and 1/4 teaspoon of pepper. Simmer for about 10 minutes.
In a large mixing bowl, combine egg with remaining 1 teaspoon salt and 1/4 teaspoon pepper, and Worcestershire sauce. Gently stir to blend; add ground beef, cooked rice, and 1 cup of the tomato mixture. Mix well. Stuff peppers with meat mixture and place in a 3-quart baking dish. Pour remaining tomato mixture over the stuffed peppers. Bake at 350° for 55 to 65 minutes. If desired, top stuffed peppers with a little shredded Cheddar cheese just before peppers are done; bake until cheese is melted.