Heat the olive oil in a large Dutch oven or deep skillet over medium-high heat. Add the chopped onion and bell pepper, then cook for 4–5 minutes until the vegetables begin to soften.

Stir in the minced garlic and cook for 30–60 seconds, just until fragrant. Keep the garlic moving so it does not brown or become bitter.

Add the ground beef and cook for 5–7 minutes, breaking it into small pieces with a spoon. Continue cooking until browned throughout, then drain excess fat if necessary.

Stir in the chili powder, cumin, kosher salt, and black pepper. Cook for a short moment so the spices coat the beef and vegetables.

Add the undrained diced tomatoes, rinsed kidney beans, beef broth, and uncooked elbow macaroni. Stir well, scraping the bottom of the pot to combine the ingredients.

Bring the mixture to a boil, then reduce the heat to medium-low. Partially cover the pot and simmer for 12–16 minutes, stirring every few minutes, until the macaroni is tender and most of the liquid has been absorbed.

Remove the pot from the heat before adding the cheese. Stir in the shredded sharp cheddar until melted and creamy.

Let the chili mac rest for 2–3 minutes. This short rest allows the sauce to thicken and cling to the pasta.

Spoon into bowls and finish with toppings such as green onions, cilantro or parsley, sour cream, diced avocado, sliced jalapeños, or extra cheddar.