Shabbat 37 - Shabbat stoves
There are three types of stoves that we will be dealing with, two-pot, and one-pot, and the trapezoidal one. The two-pot oven is called kirah, and it produces the least amount of heat of the three types. Our modern ovens are mostly comparable to this kirah.
If one heated the two-pot oven (kirah) with straw or stubble, usually there are no coals and little residual heat. Therefore, one may place cooked food upon it before Shabbat. That rule, however, if subject to further disagreements: does the word "place" means that one can leave the food there at the advent of Shabbat, or does it mean that he can even return it back after he has taken the food off on Shabbat itself? Furthermore, "cooked" does not mean that it is completely cooked, but only that a certain bandit called "Ben Drusai" who always ate his food one-third cooked, would eat it. However, there is another disagreement about food which is already cooked, but which further improves with additional cooking. The question here is can one leave this type of food on the oven, and which foods are of this type. If the oven was heated by wood, one needs to first shovel away the coals or cover them with ash. Otherwise there is a danger that he will stoke the fire.
Beit Shammai further argue with the circumstances of this rule. According to them, it is talking only about hot water but not cooked food, and it discusses only leaving the food on the stove but not returning it; Beit Hillel disagree on both counts.
Art: Philippe Lodowyck Jacob Sadee - Lighting The Stove