1. Bring a large pot of salted water to a boil. Add the pasta shells and cook according to package instructions until al dente. Drain and set aside.
2. In the same pot, heat olive oil over medium-high heat. Add the diced onion and cook until soft and translucent, about 3-4 minutes.
3. Add the minced garlic and cook for another 30 seconds, until fragrant.
4. Add the ground beef to the pot, breaking it up with a spoon, and cook until browned and no longer pink, about 5-7 minutes. Drain excess fat if necessary.
5. Sprinkle the taco seasoning over the beef and stir to coat. Add the salsa and beef broth, stirring to combine.
6. Reduce heat to medium and bring the mixture to a simmer. Let it cook for about 5 minutes, allowing the flavors to meld together.
7. Stir in the cooked pasta shells, ensuring they are well coated with the beef mixture.
8. Add the shredded cheddar cheese, stirring until it melts into a creamy sauce. Remove from heat and stir in the sour cream until smooth.
9. Season with salt and pepper to taste. Garnish with chopped cilantro if desired, and serve immediately.

This cooking process is reminiscent of the way my abuela and I would work side by side in the kitchen, creating meals that were more than just food; they were love on a plate.