Re-heating a mostly-solid food on Shabbat

Hi,

A solid which has been cooked is said to remain cooked even after it cools, such that one may re-heat it on Shabbat without concern for a new act of cooking [assuming all other halachic concerns, such as the appearance of cooking, are addressed]. Regarding liquids which have been cooked and which have then cooled, though, there is significant doubt, and we rule strictly to prohibit re-heating.

Regarding a food which is mostly solid, but which contains some liquid, the sources are unclear. Therefore, one may not re-heat such a mixture, other than in very extenuating circumstances.

(Rav Moshe Feinstein, Igrot Moshe Orach Chaim 4:74:7)

Have a great day,
Mordechai