Can someone remove frozen bread or chaalah on shabbos in preparation for melave malke so that the bread will be defrosted for malave malke?
It is forbidden to remove bread from the freezer for the purpose of melaveh lemalkah. This is considered hachanah, preparation from Shabbos for the weekday, and is not permitted.
However, if it is possible that the challah will be eaten for se’udah shelishis, then it is permitted.
Sources: See Magen Avraham 323:8; Mishnah Berurah 323:26, 336:33.