Cook the pasta: Bring a large pot of salted water to a boil. Add the pasta and cook according to the package instructions until al dente. Drain the pasta and set aside.

1. Cook the ground beef: While the pasta is cooking, heat olive oil in a large skillet over medium-high heat. Add the ground beef and cook, breaking it apart, until browned and fully cooked through (about 6-8 minutes). Drain any excess fat.
2. Sauté the onion and garlic: Add the diced onion to the skillet with the beef and cook for 3-4 minutes until softened. Add the minced garlic and cook for another 30 seconds until fragrant.
3. Add the taco seasoning: Stir in the taco seasoning, and add salt and pepper to taste. Add the diced tomatoes and beef broth, stirring to combine. Let the mixture simmer for 5-7 minutes, allowing the flavors to meld together.
4. Combine the pasta and sauce: Add the cooked pasta to the skillet with the beef mixture. Stir to combine, ensuring the pasta is evenly coated in the sauce.
5. Add the creaminess: Stir in the sour cream and half of the shredded cheese, letting it melt into the mixture for a creamy, cheesy texture.
6. Top with cheese: Sprinkle the remaining cheese over the top and let it melt for 2-3 minutes, until bubbly and golden.
7. Serve: Garnish with fresh cilantro and any additional toppings you like, such as diced avocado, salsa, or jalapeños. Serve immediately.