Mash potatoes (adding butter and milk if preferred). Boil macaroni until almost cooked thru. Meanwhile, fry ground beef and onion together, drain fat and mix with tomato soup. Mix meat and cooked macaroni together and put in sprayed casserole dish. (Mixture should be nicely coated in the soup. You want it very moist. Add water or tomato juice if its a bit on the dry side) Cover mixture completely in the mashed potatoes. Bake in 350 degree oven for 30 mins until potatoes start to brown. Let set 5 mins before serving. Enjoy! **For a great option to this dish, add some shredded cheese to macaroni mixture or sprinkle some on top of potatoes for a nice garnish.