From the refrigerator – it’s best to reheat in a skillet over the stove top. Pour some oil into the skillet and reheat to crisp the edges slightly. Reheat gravy in a saucepan with 1 or 2 tablespoons chicken or beef stock or water until it’s a pourable consistency. From the freezer – thaw the omelet and gravy in the refrigerator and reheat as mentioned above.