Simple Tuna Noodle Casserole

1.5 lbs. Macaroni or Noodles
1 Stick of Butter (add an another stick of butter if adding bread crumb topping.)
1 Large Onion, chopped
2 10oz cans Cream of Mushroom or Celery soup
2 soup cans Milk
3 or 4 cans Tuna, drained
8 oz Sharp Cheddar Cheese
Optional: Bread Crumbs for topping

Cook macaroni according to package directions.  Melt butter and saute onion in it until onion turns clear. Stir in soup and milk.  Mix with cooked macaroni and bake in casserole dish about 45 minutes at 350 degrees.  We generally top with bread crumbs and butter mixture.  Melting an additional stick of butter and adding enough bread crumbs to make right consistency for topping.  Add to top of casserole before baking.