In well greased 9 x 13 casserole dish add the precooked macaroni shells. Next in a separate large bowl combine 2 cans of drained tuna, mushrooms, sweet peas, 1/2 cup of bread crumbs, mushroom soup, celery soup,milk, shredded cheese, salt and pepper to taste.
Mix all ingredients well and add to the macaroni and stir all well until incorporated. In a separate bowl mix remainder bread crumbs and melted butter and sprinkle over the tuna casserole. Cover with aluminum foil and bake at 350F/180C for 30 minutes and then remove foil and bake 5-10 more minutes until browned.