On both recent flights I had; BKK AUH ORD; there was someone in the J cabin ( it was the 777-300er) in a white coat. Is this the chef person?
In both instances the white coat served the starboard aisle and the cabin manager (? I don't know the technical term for EY) served the port aisle.

Food was pretty good and variations could be had on the long AUH ORD sector. The wine and liquor could be of a greater range and higher quality.