Cut tops off peppers, remove seeds, keeping tops. Sauté meat in a frying pan, until browned. Add mushrooms, onion, garlic, carrots and celery. Season with salt & pepper. Add remaining ingredients. Stuff peppers and place in a baking dish. If you have more stuffing than will fit inside peppers, allow them to overflow into the dish. Add ½ cup water to baking dish, cover and bake over, bake at 350°F for 30 minutes.