This was a favorite of ours as kids. Cooks up fast and can increase amounts to feed larger crowds.

1lb ground beef
1/2 onion chopped fine (can substitute dried minced onion 2 tbsp.)
1 box elbow macaroni
2-14oz cans Ro-tel chopped tomatoes (or your favorite brand)
1 tablespoon minced garlic
3 tbsp. Worcestershire sauce
2 packages of pork gravy (can use 2 cans prepared gravy)
1 can mushrooms
Salt and pepper to taste
1 cup water

Brown hamburger and onion together (drain fat). Place tomatoes, garlic, mushrooms, gravy, Worcestershire, water, salt and pepper in large pot and place on medium heat while hamburger is cooking, stir occasionally. Put hamburger in when finished cooking. Cook macaroni to package directions and drain. Place in pot with rest of ingredients. Serve and enjoy.