What is the ruling on eating meat in restaurants in European countries when one does not know if it was slaughtered according to Islamic law?

It is necessary to avoid eating meat in Western countries, with the exception of fish and meat sold by shops that slaughter according to Islamic methods.

Scholars are in agreement regarding the prohibition of carrion (maytah), which is an animal that died without lawful Islamic slaughter. Most of the slaughtered animals in those countries fall under this category, such as those drowned or electrocuted. Eating pork is also forbidden.

It is not permissible to argue based on the generality of Allah’s statement: "And the food of those who were given the Scripture is lawful for you" [Al-Ma'idah:5], because scholars have exempted carrion and pork from the general permissibility of the People of the Scripture's food, as they are forbidden in themselves.