Brown the meat: Heat olive oil in a large heavy pot over medium-high heat. Add ground beef and cook, breaking it up, until browned and no longer pink, about 5–7 minutes. Spoon off excess fat if needed.
Soften aromatics: Add the diced onion and cook until translucent, about 3 minutes.
Stir in garlic and cook 30 seconds until fragrant.
Season well: Sprinkle in taco seasoning, cumin, and smoked paprika. Stir to coat the meat and onions so the spices toast slightly.
Add liquids and tomatoes: Pour in the diced tomatoes with green chiles, tomato sauce, and broth. Stir to combine and bring to a steady simmer.
Add the pasta: Stir in the dry pasta.
Reduce heat to medium, cover partially (lid slightly ajar), and simmer, stirring every few minutes to prevent sticking. Cook until the pasta is just tender and most liquid is absorbed, about 10–12 minutes depending on shape.
Make it creamy: Reduce heat to low. Stir in sour cream until smooth and blended.
Add the cheese: Sprinkle in cheddar and Monterey Jack a handful at a time, stirring until melted and glossy.
If the mixture seems too thick, splash in a bit more warm broth or water.
Taste and finish: Season with salt and pepper. Let it rest for 2 minutes to thicken. Serve hot with your favorite toppings.