01 - Heat olive oil in a large pot or Dutch oven over medium heat. Add the ground beef and cook until browned, breaking it apart with a spoon, about 5 minutes. Drain excess fat if needed.
02 - Add the diced onion, minced garlic, and diced bell pepper to the pot. Sauté for 3 to 4 minutes until the vegetables are softened and fragrant.
03 - Stir in the chili powder, ground cumin, smoked paprika, salt, black pepper, and cayenne pepper. Cook for 1 minute until the spices are fragrant and well combined with the meat mixture.
04 - Add the tomato paste and cook for 1 minute, stirring constantly. Stir in the diced tomatoes and drained kidney beans until evenly incorporated.
05 - Pour in the broth and bring to a simmer. Stir in the uncooked elbow macaroni. Reduce heat to low, cover, and cook for 10 to 12 minutes, stirring occasionally, until the pasta is tender.
06 - Remove from heat and stir in the butter and milk. Add the shredded cheddar cheese and stir until completely melted and the sauce is smooth. Adjust seasoning to taste.
07 - Serve hot, garnished with extra shredded cheese or chopped green onions if desired.