What is the ruling on owning a mixed-gender restaurant where men and women sit in the same area, serving halal food and avoiding forbidden items, knowing that there is a possibility of a male and female sitting at the same table, even if their relationship is illicit or to reduce waiting time?

The restaurant owner is only held accountable for his actions and is not responsible for the deeds of his customers. If one of them commits an objectionable act or a sin without the owner's assistance, then it is on the individual themselves. Allah says: "And whoever earns a sin, he earns it only against himself." A Muslim is obligated to enjoin what is good and forbid what is evil to the best of their ability, and according to the Islamic legal guidelines.