If you want to only reheat a small amount of the dip (say, 1 - 2 cups), I've had great success using the microwave; just place the dip in a microwave-safe bowl (covered with a paper towel to catch any spatter!) and microwave on high in 30 second increments, stirring in between, until hot. If you want to reheat a larger amount, I recommend using the stovetop. Just place the dip in a skillet or saucepan set over low heat, stirring frequently until the dip is heated through. And, don't forget to slice up a fresh green onion to garnish the top before serving!