ADAIR, according to the opinions that one must garuf and katum his oven even if the food is Maachal ben Derusai, he doesn't have to if the food is Mitztamek veRa Lo [the longer you cook it the worse it gets] (in contrast to Mitztamek veYafe lo [the longer you cook it the better it gets).
The Gemara in Perek Kira in Shabbos gives a few foods which are Mitztamek veYafe lo. Are there any modern foods considered in this category (mentioned by poskim).
Out of curiosity, is Cholent in that category?
Every Rov I have ever spoken to has used Cholent as the ideal example of a Mitztamek veYafe lo.
In "Shabbos Kehalacha" (Chelek Aleph Perek Ches), Rabbi Yekusiel Farkash defines mitztamek veyafa lo as a food that the individual benefits from its continued cooking after reaching nisbashel kol tzorkoy, regardless of the benefit to the dish itself. He gives the example of meat that gets shriveled up and soft through additional cooking; if the meat will be used only for his family he would be happy to have it softer and it is mitztamek veyafa lo, however if he is expecting guests it is mitztamek verah lo since he wishes to give them presentable portions and not shriveled meat. He extends this to health concerns; if for medical concerns influence how well done the food should be, that will cause it it to be mitztamek vetov/verah lo.
In ha'orah zayin he deals with foods that are specifically mentioned in achronim to be considered mitztamek vetov lo, and discuses when an egg would fall under that category.
