Yes, you can make the tteokbokki ahead of time and reheat it just before serving. There are a few tips you may need to pay attention to when making the tteokbokki in front of time. First, slightly undercooked the rice cake while cooking the tteokbokki, so it won't be too soft and mushy after reheating. Next, allow the cooked tteokbokki to cool down to room temperature before storing it in an airtight container. Place it in the refrigerator promptly and keep it chilled until you're ready to reheat and serve. Last but not least, if the tteokbokki sauce is too thick after chilling, you may add a little water or broth when reheating to loosen up the texture.