Preheat your oven to 350. Spray a 9 by 13 inch pan with cooking spray and set aside.
Boil a large pot of water and cook the shells according to package instructions (see note). When the shells are finished cooking, drain them and rinse them with cold water to stop the cooking process.
In a large skillet over medium heat, heat up the oil. Add in the onion and garlic and saute for 5 minutes until the onions are translucent. Add in the turkey and break up, cooking it until it is browned. Drain any excess grease from the skillet.
Add in the tomato sauce and taco seasoning. Bring to a simmer and then turn low. Cook for 5 minutes stirring occasionally. Stir in the frozen corn.
Spread half of the salsa over the bottom of the pan. Spoon a small amount of the turkey mixture into 24 shells (you will have shells left over), placing them seam side up on the salsa. Top with the remainder of the salsa and then add the shredded cheese.
Cover with tin foil and bake for 30 minutes. Remove the foil and bake for another 3 to 5 until the cheese is nice and melty.
Serve with toppings, like green onions, jalapeños, olives, shredded lettuce, and tomatoes, and enjoy!