Preheat your oven to 350ºF.
Fill a large pot with water and bring to a boil. Cook the shells in the boiling water for about 13 minutes. They will still be slightly firm but that’s okay; they will continue to cook in the oven later on.
Drain the shells and set them aside.
Add the ground beef to a large skillet and cook over medium high heat, chopping up the beef as it cooks to make small crumbles. Cook the beef for about 6-8 minutes. It will just be starting to brown.
Stir in the taco seasoning and chicken broth. Cook the meat for another 5 minutes. The broth will begin to thicken.
Stir the refried beans and corn into the skillet and then add ¾ cup of the shredded cheese to the skillet and stir, melting the cheese into the meat and beans.
Pour ½ cup of the salsa into the bottom of a 9x13 casserole dish.
Scoop about ⅓ cup of the ground beef mix into each cooked pasta shell, placing the shell into the casserole dish after you stuff it with the meat. I like to use a large soup spoon to scoop the meat but you can also use a ⅓ cup measuring cup to stuff them with exactly the same filling.
Pour the remaining salsa over the shells, covering them evenly.
Place the shells in the preheated oven and bake for 35-40 minutes. If the shells start to look to brown or crisp, loosely cover the casserole dish with foil.
Remove the shells from the oven and immediately sprinkle them with the remaining ½ cup of shredded cheese.
Top the shells with a drizzle of sour cream then serve while warm!