There are various types of ready-to-eat or instant jellyfish products, which can be found in most Asian supermarkets. There are some which contain only heads and some which contain tentacles; any type will work for this recipe, as long as it isn’t the salted dried type. Ready-to-eat jellyfish is typically sold in 5.2-ounce packages with seasoning packets. If you purchase packages of another size, make sure you have at least 10 ounces of jellyfish once you remove the seasoning packets. You will have extra pickled vegetables. Save for another use, such as sandwiches.