In a 3 qt pot, boil a slightly salted pot of water.
Cook macaroni al dente(deduct 2 minutes from the cook time).
Make mac and cheese according to package directions.
add milk and cheese(optional).
In a 10 inch deep fry pan, Brown meat.
add chopped onion,salt and pepper.
drain any grease.
Mix in cream of mushroom soup and water(or Milk)(make sure meat is cooked through).
In an oven-proof bowl layer 1/2 the meat then 1/2the macaroni then repeat, (Macaroni ends up on top)cover with alumium foil, bake for 20-30 minutes in a 350 degree oven.
(If time is a problem just mix all together in macaroni pot, cover and let simmer for 10 minutes.