Prepare the shells and place in a disposable aluminum pan (or freezer-safe and oven-safe dish). Cover tightly with foil and freeze for up to 3 months. Be sure to label including the date prepared. Thaw overnight in the refrigerator. Bake covered at 375 degrees for 30 minutes. Uncover and bake another 5-10 minutes. If the shells are still partially frozen when baking, allow an extra 10-15 minutes of bake time.