Chop up all seasonings. Put oil in heavy cooking pot and heat. Sautee over a low heat: celery, green onions, yellow onions, bell pepper, and garlic. Parboil mirlitons. Peel skin. Process mirliton in blender or food processor. Add salt and pepper. Add mirliton to cooked seasonings and add shrimp also. Heat until cooked. Stir in French bread pieces, soaking up all juices. Stir in 1 well beaten egg. Place in casserole dish. Top with French bread crumbs and bake in 350 degree oven until bread crumbs are toasted and food is bubbling. Remove from oven and serve.