Question:
Cruise offers kosher airline meal type meals for daily lunch and dinner. Is it halachically permissible to eat if warmed up by non-Jew on Shabbos (presumably with microwave)?
Answer:
We are not allowed to benefit from melacha that a gentile does for us on Shabbos. Therefore he can eat the food but only after it gets cold, in order that he should not benefit from the melacha that the gentile did for him. It is not considered as benefitting from the action of the gentile regarding the cooking of the food because it is already cooked, however the fact that now the food is warm, is a benefit from the action of the gentile. Therefore, he has to wait until the food cooks down.
Sources:
M:B 253-34, 96.
