This is the Authentic Mexican Sopita recipe.

In a medium saucepan add olive and warm over medium heat. Add in uncooked pasta shells and diced onion.
Cook for 5-6 minutes until the pasta has browned and the onions have softened. Make sure to keep stirring to avoid burning.
Add in broth and tomato sauce and stir. Simmer for 10-12 minutes until the pasta is cooked through and has soaked up the majority of the broth.
Serve as is or garnish with desired toppings
Enjoy !!