I always keep a bag of lentils from Puy in my pantry since they can be prepared really quickly and they're a greatsidedish, equally good served warm or at room temperature.
They are great to heat quickly in the microwave as an easy sidedish, you can mix onion and peppers into scrambled eggs, top baked potatoes with broccoli, add mixes to soup and stews and tacos, or toss into stir fry.