The Mishna in Avodah Zarah (35b) records various foods that are Rabbinically prohibited when they originate from non-Jews. This list includes shelakos – cooked vegetables. Rashi (s.v. vehashelakos ) comments that Chazal’s objective was to prevent intermarriage by distancing us from our non-Jewish neighbors. From the Talmud’s discussion on the rules of cooked vegetables (ibid 38a) it is clear that the Rabbinic dictum included other cooked foods, as well. The Talmud quotes two statements from the same amora concerning the parameters of this Halacha. According to some, Rav Shmuel bar Yitzchak stated in the name of Rav that any food normally eaten raw is not subject to the laws of bishul akum. In others’ opinion, Rav Shmuel bar Yitzchak stated that anything that does not ascend the table of kings as a condiment is not prohibited when cooked by a non-Jew. The Baalei HaTosafos (ibid. s.v. ikah ) quote the ruling of Rabbeinu Tam that we follow both of these quotations. Since bishul akum is a rabbinic prohibition, it is subject to the rule that in matters of rabbinic law we follow the more lenient opinion. Rabbeinu Tam’s ruling is accepted in Shulchan Aruch (Y.D. 113, 1).

The Shulchan Aruch rules that a non-Jew may cook all foods if a Jew contributes to the cooking process, even if the Jew participates minimally. In the view of the Shulchan Aruch, a Jew must either place the food on the fire or stir the food once it is on the fire. However, the Rama (ibid.) quotes the ruling of several Rishonim that it is sufficient for the Jew to light the fire on which the pots will eventually be placed. (Alternatively, he can stoke the coals of a previously lit fire or add a small amount of fuel to the fire.) The Rama quotes that some Rishonim maintain that it is adequate for the non-Jew to light the stove from another flame kindled by a Jew. Consequently, a non-Jew may ignite burners on a stove from a pilot light lit by a Jew. Many restaurants and private individuals frequently utilize this leniency.

Another leniency is advanced by Rav Avraham b. David ( quoted in Tos. 38a s.v. ela and Tur ibid.) He opines that the rabbinic dictum only applies to food cooked on non-Jewish premises but not to food cooked in a Jew’s home. The opinion of the Raavad is not generally accepted in and of itself.[1]

However, the Taz (s.k. 6) suggests that the Rama’s ruling permitting a fire taken from a fire lit by a Jew is too lenient. Therefore, he is comfortable relying on it only in concomitance with the opinion of the Raavad. That is, if a Jew lit the pilot light and the cooking is taking place in a Jewish establishment, the food is permitted. Yet, if a Jew lit the pilot light in a home or restaurant owned by a non-Jew, the food is still subject to the prohibition of Bishul Akum. This can provide many complications in restaurants owned by non-Jews.

The Zer Zahav(glosses to the Isser V’Heter HaAruch ) and the Minchas Yaakov (in his glosses to the Rama’s Toras Chatas ) disagree with the Taz’s stringent requirement. They do not believe that one must combine the rulings of the Rama and Raavad. Rather, they assume that the ruling of the Rama alone is sufficient to permit the food. According to their ruling, a non-Jew may even cook on non-Jewish premises with a stove kindled from a pilot light lit by a Jew.

[1] Ostensibly it is not quoted in Shulchan Aruch. Yet some suggest that the opinion of the Raavad is the reasoning behind the ruling of the Rama (ibid. 4.) that Bishul Akum does not apply to food a maid cooks in a Jewish home. See Shach s.k. 7.