What is the ruling on eating at foreign restaurants in Muslim countries, and is it obligatory to ask about the permissibility of the food?

If by foreign restaurants, one means restaurants owned by non-Muslims, then eating in them follows the ruling on eating the food of disbelievers.

It is permissible to eat fruits, plant-based foods, and fish.

As for meat: if those managing the restaurants are People of the Book or Muslims, then the meat is originally permissible, unless there is widespread knowledge that it is not slaughtered according to Islamic law. In such a case, one must ascertain its source and the religion of the slaughterer.

It is advisable to refrain from eating meat in such restaurants to avoid doubts, especially given the abundance of Muslim-owned restaurants.