Brown the ground beef and diced onion in a large pot over medium-high heat. Drain any excess fat.
Stir in the tomato paste, garlic powder, and chili powder, cooking for 1 minute.
Pour in the beef broth and bring the mixture to a boil.
Stir in the uncooked elbow macaroni. Reduce the heat to a simmer and cook uncovered for 13-15 minutes, stirring occasionally, until the pasta is tender and most of the liquid is absorbed.
Remove the pot from the heat. Stir in the grated cheddar cheese until melted and creamy. Season with salt and pepper to taste.
Notes
Store leftovers in an airtight container in the refrigerator for up to 3-4 days.