In a large pot, set over medium-high heat, add the lean ground beef and chopped onion. Cook for about 7-10 minutes, stirring frequently, until the beef is browned and the onions are tender.

Once the beef mixture is nice and brown, carefully drain any excess fat from the pot. Stir in the tomato paste, garlic powder, and chili powder. Cook for an additional 2-3 minutes.

Pour in the beef broth and bring the mixture to a rolling boil over high heat, about 3-4 minutes.

Stir in the uncooked elbow macaroni. Reduce heat to medium and let it simmer uncovered for about 13-15 minutes, stirring occasionally.

Once the macaroni is cooked to al dente, remove the pot from heat. Immediately stir in the freshly grated cheddar cheese until melted.

Allow the dish to sit for a couple of minutes before serving.