Heat a large pot or deep skillet over medium heat. Add ground beef and cook until browned. Drain excess fat if needed.
Add onion and cook until softened. Stir in garlic and cook until fragrant.
Sprinkle in taco seasoning, salt, and pepper. Stir well to coat the meat.
Add diced tomatoes, broth, and dry pasta. Stir to combine.
Bring to a gentle simmer, cover, and cook 12–15 minutes, stirring occasionally, until pasta is tender and sauce thickened.
Reduce heat to low. Stir in shredded cheese until fully melted and creamy.
Remove from heat and rest 3–5 minutes before serving. Add toppings if desired.