Is it permissible to eat chicken and meat in restaurants without verifying that they have been slaughtered according to Islamic law?

Narrated by Aisha (may Allah be pleased with her): Some people came to the Prophet (peace and blessings of Allah be upon him) and said: "Some people bring us meat, and we do not know whether they mentioned the name of Allah over it or not?" He said: "Mention Allah's name over it yourselves and eat." This Hadith (definition) indicates the permissibility of eating even if we do not know whether the slaughterer mentioned Allah's name or not, or whether it was slaughtered in a proper manner or not. This is because the default for an action performed by its doer is validity and permissibility unless there is evidence to prove its prohibition. This is part of Allah Almighty's facilitation for His servants. Therefore, it is not a condition to inquire about the method of slaughter or the mention of Allah's name; rather, it is permissible until proven otherwise.