Local residents admitted to "being on edge" after a second fire on the same road in Golders Green in four days.
However, the blaze at Taboon restaurant on Russell Parade, Golders Green Road, turned out to be caused by an industrial chip pan.
Four fire engines and the police rushed to the scene of the incident, which occured on the roof of the eatery at around 7pm on Wednesday.
The blaze was quickly extinguished and there were no injuries, despite the presence of ambulance crew.