Leftover couscous or pilaf should be refrigerated in a tightly sealed storage container or zip lock plastic bag. To reheat, add 1 to 3 tablespoons water for each cup of leftover couscous or pilaf (couscous may need more water depending on the wattage of your microwave as it tends to dry out faster than pilaf). Stir gently while cold. Reheat in the microwave oven. Couscous and pilaf can also be reheated over medium low heat in a saucepan on the stove, stirring occasionally.