Boil the pasta shells in a generous amount of lightly salted water until just tender, about 10 minutes. Drain well, cool in cold water, and drain well again.
Spoon and combine the pasta sauce and ½ cup water into the bottom of a 9” × 13” casserole dish. Combine the turkey, egg, breadcrumbs, Parmesan cheese, oregano, garlic, milk, salt and pepper in a bowl. Stuff about 2 Tbsp. amounts of the turkey mixture into each shell.
Set the stuffed shells on top of the sauce in the casserole. Divide and top each shell with a generous amount of the mozzarella cheese. (Stuffed shells can be made to this point up to a day before needed. Cover and refrigerate until ready to bake.)
Preheat the oven to 375 degrees F. Cover the dish with foil and bake 30 minutes. Remove the foil and bake for 10 to 15 minutes more, or until the tops of the shells are golden and the sauce is bubbling. Serve shells, topped, if desired, with chopped parsley.
Note: Tomato basil pasta sauce is available in our canned tomato product aisle.