01 - Bring a large pot of salted water to a rolling boil. Add elbow macaroni and cook until just al dente. Drain through a colander and set aside.
02 - Heat a large skillet or Dutch oven over medium-high heat. Add ground beef and cook, breaking it apart with a spoon, until thoroughly browned. Drain off any excess fat.
03 - Add the diced onion, minced garlic, and diced red bell pepper to the browned beef. Sauté for 4 to 5 minutes, stirring occasionally, until the vegetables have softened and the onions turn translucent.
04 - Stir in the chili powder, ground cumin, smoked paprika, dried oregano, salt, and black pepper. Cook for 1 minute, stirring constantly, until the spices are fragrant and well incorporated.
05 - Pour in the diced tomatoes with their juices, tomato paste, and drained kidney beans. Stir to combine. Bring the mixture to a gentle simmer and cook for 8 to 10 minutes, stirring occasionally, until the flavors meld and the sauce thickens slightly.
06 - Reduce heat to low. Add the cooked macaroni, milk, and shredded cheddar cheese to the skillet. Stir continuously until the cheese has completely melted and the pasta is evenly coated in the creamy sauce.
07 - Taste the finished dish and adjust salt and pepper as needed. Serve immediately while hot, garnished with fresh cilantro, sliced green onions, or additional shredded cheese if desired.