No matter the occasion, whether it's a weekday dinner or a holiday party, lasagna offers a hearty, home-cooked meal that provides tasty leftovers. Lasagna generally consists of layers of pasta, ricotta cheese, mozzarella cheese, sauce and meat. The thickness of the dish typically requires about an hour of bake time when uncooked. Heat precooked lasagna in the oven for a no-fuss entrée that retains its flavor and consistency.
Preheat the oven to 350 degrees.
Thaw frozen, precooked lasagna in the refrigerator for 24 hours. Place the whole lasagna or individual slices in an oven-safe, glass dish.
Cover the pan tightly with tin foil to lock in heat and moisture. This prevents the lasagna from drying out while heating.
Place the pan on a middle shelf in the oven and heat the lasagna for 20 to 25 minutes until the cheese bubbles and the interior of the lasagna is hot to the touch.