01 - Bring a large saucepan of salted water to a rolling boil. Add elbow macaroni and cook according to package directions until al dente. Drain through a colander and set aside.
02 - Heat olive oil in a large skillet or Dutch oven over medium heat. Add the chopped onion and sauté for 3 minutes until softened and translucent.
03 - Stir in the minced garlic and diced red bell pepper. Continue sautéing for 2 minutes until fragrant and the pepper begins to soften.
04 - Add the ground beef to the skillet, breaking it apart with a wooden spoon. Cook until thoroughly browned and no pink remains. Drain off any excess fat.
05 - Sprinkle in the chili powder, ground cumin, smoked paprika, salt, and black pepper. Stir continuously for 1 minute to bloom the spices and release their aromatic oils.
06 - Stir in the tomato paste, canned diced tomatoes, drained kidney beans, and beef broth. Mix thoroughly to combine all ingredients and bring the mixture to a gentle simmer.
07 - Reduce the heat to medium-low and let the chili simmer uncovered for 10 minutes, allowing the flavors to meld and the sauce to reduce and thicken.
08 - Fold in the cooked macaroni, milk, shredded cheddar cheese, and half of the mozzarella. Stir continuously until the cheeses are fully melted and everything is evenly coated.
09 - Scatter the remaining mozzarella across the surface. Cover the skillet and let rest off the heat for 2 to 3 minutes until the cheese melts, or briefly place under a broiler for a golden, bubbly crust.
10 - Serve immediately while hot, garnished with additional shredded cheese or fresh herbs as desired.