Tomato, Cheddar and Beef Macaroni

1 lb ground beef
1 cup chopped onion
1 can (14.5-oz) diced tomatoes with basil, garlic and oregano
1 cup water
1 cup elbow macaroni
1 1/2 cups shredded cheddar cheese
Brown the ground beef with the onions, drain. Stir in the tomatoes, water, and macaroni. Cover and simmer 10 minutes or until tender; stir in cheese and serve.