Option 1

Pull Mark aside immediately for a private, direct conversation, expressing your concern about his behaviour and the safety risks, and strongly advise him to leave and get help.

Option 2

Immediately inform the head chef or restaurant manager about Mark's condition, explaining the safety concerns and the impact on the kitchen's operation.

Option 3

Try to cover for Mark's mistakes and pick up his slack without saying anything, hoping he will sober up or that no one else notices his impairment.