One may reheat fully cooked food on Shabbat, because the prohibition of bishul applies when one changes the status of food from raw to cooked. However, once a food is cooked one may reheat it, but what about changing food’s status from cooked to roasted, or from baked to cooked, etc.?

We know that there is no prohibition of cooking something that has already been cooked, and we also know that this Halacha is only regarding dry and solid food. but we cannot rewarm liquid food. What is the Halacha if the food is congealed but will liquefy when reheated?