Baruch Liberman wrote:
My 14 year old daughter, Batsheva, does quite a bit of baby-sitting and occasionally sits for non-Jewish neighbors. What should she do if she is asked to warm up dinner or a pizza for the children? Would she be violating the laws of kashrut?
Dear Baruch Liberman,
She might be violating the Torah command "Don't cook a kid in its mother's milk."
With one exception, it's permitted to cook non-kosher food. That exception is milk and meat. "Don't cook a kid in its mother's milk" means the very act of cooking milk and meat is prohibited, even if you don't plan to eat it.
This prohibition can apply even to milk and meat absorbed into cooking utensils. A pot owned by someone who doesn't keep kosher probably has milk and meat absorbed into the substance of the pot. So even if the food itself contains no milk and meat, your daughter is forbidden to heat it up using the family's cook-wear.
One solution (which should only be done with the parents' permission) is that your daughter put the pot on the stove and supervise while one of the children lights the fire; or that she first light the fire and supervise while the child places the pot.
By the way, the prohibition of cooking milk and meat applies to meat from kosher-type animals only. So, for example, if the pizza has ham on it, your daughter may heat it in a clean microwave on a paper plate. Bon Appetite!
This brings to mind a story told of Rabbi Yaakov Kaminetzky, zatzal. The Talmud says that a person shouldn't say, "I don't want non-kosher food." Rather he should say, "I want it, but what can I do...the Torah prohibits it!" Near Rabbi Kaminetzky's yeshiva stood a pizza shop. When passing by, Rabbi Kaminetzky would sometimes whiff the enticing aroma of non-kosher pizza, smile, and say "Ahh, smells delicious!"
- Exodus 34:26, Chullin 155b
- Rema in Shulchan Aruch, Yoreh Deah 87:1
- Gilyon Maharsha 87:6
- Pri Megadim Yoreh Deah 105:2 in Mishbetzot Zahav