01 - In a large pot or Dutch oven over medium-high heat, cook the ground beef, breaking it apart until evenly browned and cooked through, about 5 to 6 minutes. Drain excess fat if needed.
02 - Add chopped onion, diced red bell pepper, and minced garlic to the pot. Cook, stirring frequently, until softened, approximately 4 minutes.
03 - Stir in chili powder, ground cumin, smoked paprika, dried oregano, optional cayenne pepper, salt, and black pepper. Cook for 1 minute until aromatic.
04 - Add diced tomatoes, tomato sauce, beef broth, drained kidney beans, and uncooked elbow macaroni. Stir thoroughly to combine all ingredients.
05 - Bring mixture to a boil, then reduce heat to low. Cover and simmer, stirring occasionally, until pasta is tender and sauce has thickened, about 12 to 15 minutes.
06 - Remove from heat, evenly sprinkle shredded cheddar cheese over the top, cover, and let stand for 2 to 3 minutes until cheese melts.
07 - Optionally garnish with sliced green onions or chopped cilantro before serving. Serve hot.