1. In a large pot, cook the ground beef over medium heat until browned. Drain any excess fat.
2. Add the chopped onion and minced garlic to the pot. Cook until the onion is translucent.
3. Stir in the chili powder, ground cumin, salt, and black pepper. Cook for another minute.
4. Add the kidney beans, diced tomatoes, and elbow macaroni to the pot. Stir well to combine.
5. Pour in enough water to cover the mixture. Bring to a boil, then reduce the heat to low. Simmer for about 20 minutes, or until the macaroni is tender.
6. Stir in the shredded cheddar cheese until melted and well combined. Serve hot.