Eating in a regular restaurant on a Christian feast

Q 17: I usually have my lunch at a certain restaurant; is it lawful to go to it on a special festival day when many non-Muslims come, knowing that on that day they prepare special food for this occasion? A: It is not permissible to have such food in order to avoid mixing with non-Muslims at their festivals. If it is due to coincidence, it would be permissible to eat from that food provided that it was made by the People of the Book (i.e. Jews or Christians), so long as it contains no unlawful ingredients, such as pork for example. If the food is made by other than the People of the Book, it will not be permissible to eat any of the kinds of meat served. Allah, Glorified be He, does not allow Muslims to eat the food of non-Muslims, except for the People of the Book. Food here means the meat of the animals that they slaughter. (Part No. 1; Page No. 452

A: It is not permissible to have such food in order to avoid mixing with non-Muslims at their festivals. If it is due to coincidence, it would be permissible to eat from that food provided that it was made by the People of the Book (i.e. Jews or Christians), so long as it contains no unlawful ingredients, such as pork for example. If the food is made by other than the People of the Book, it will not be permissible to eat any of the kinds of meat served. Allah, Glorified be He, does not allow Muslims to eat the food of non-Muslims, except for the People of the Book. Food here means the meat of the animals that they slaughter. (Part No. 1; Page No. 452) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.