The incident happened in Green Lanes near Aldermans Hill at around 2.50pm yesterday (April 15).
Officers and London Ambulance Service crews attended and found a man who had been stabbed.
He was taken to hospital for treatment where his injuries were assessed as non-life-threatening.
No arrests have been made as police enquiries continue.
A spokesperson for Metropolitan Police said: “At around 14:50hrs on Tuesday, 15 April police were called by the London Ambulance Service to reports of a man being stabbed in a restaurant on Green Lanes, N13.
“Officers attended the scene and one man, aged 19, was taken to hospital for stab wounds. His injuries are not life-threatening or life-changing.
“No arrests have been made at this early stage and investigations remain ongoing.
“Anyone with information is asked to call 101 or ‘X’@METCC and quote 4140/15APR25.”
