Preheat oven to 350 Degrees F. Pour 1/2 cup pasta sauce into bottom of two 9 x 13 inch baking dishes.
Cook shells according to package directions until al dente. Drain and set aside while you prepare the ricotta. Be sure not to overcook shells as they will break. Once drained I like to place onto a baking sheet sprayed with cooking spray to keep them from sticking to each other.
Place Ricotta, shredded chicken, Parmesan, mozzarella, pesto, salt, pepper and garlic salt into a large bowl, stirring to combine. Scoop about 2 tablespoons into each cooked shell and place side by side into the baking dish. You can place seam side down or up. I placed mine up today. Top each baking dish with shells then spoon sauce evenly over each shell. Top with fresh shredded mozzarella cheese and bake for 30-35 minutes, until hot and melted. Before serving top with sliced fresh parsley or basil.