Question: Is it permissible to eat foods prepared by Christians and Jews?
Answer: Since the followers of the past revealed religions (that is, the Jews, the Christians and the Zoroastrians) are ritually pure, many of the problems concerning the status and permissibility of the food are resolved when we live with them. It becomes permissible for us as Muslims to eat from their food no matter whether they touched it with their wet hands or not, as long as we do not know or are not sure that it consists of what is forbidden to us, like Haram meat.
Ayatollah Al-Sayyid Ali Al-Husseini Al-Sistani