Heat olive oil in a large pot over medium heat.
Add ground beef and cook until browned, breaking it apart as it cooks.
Toss in the diced onion and garlic, and cook for another 2-3 minutes until softened.
Stir in taco seasoning, beef broth, salsa, and diced tomatoes. Mix it all up.
Add the pasta shells, give it a good stir, and bring to a boil.
Reduce the heat, cover, and let it simmer for about 12-15 minutes or until the pasta is tender.
Remove the lid and stir in the shredded cheese until melted and creamy.
Taste and adjust with salt and pepper, then serve it up hot. Top with cilantro or a dollop of sour cream if you’re feeling fancy.