Generously butter a 2-quart casserole. Drop in toast torn in small pieces. Set aside. Sauté in butter the onion, celery, and green pepper in a small skillet until soft. Add tomatoes, sugar, oregano, Bouquet Garni, salt and pepper to onion mixture and mix together. Place in casserole over toast. Bake at 350^ until bubbly and thick, about 1 hour. Grated Parmesan cheese may be added to top before baking.