Chazara, Shiyah: The halachos of returning food to the fire on shabbos. - If one rises early (on Shabbos morning) and finds that the food in his pot is beginning to burn, if he is concerned that it might burn more, he may remove it, place a used empty pot on the mouth of the Kirah, and then put the pot containing the food atop the empty pot. One should be careful not to place the pot (containing the food) on the ground and it should be boiling hot. (It has already been stated that it is customary to be lenient (and permit returning a pot to a stove) even where it has been placed on the ground).