Vloglady,i grew up and still live in East London which was, when i was a child,full of "Cockneys".Most of them had moved out by the 1970`s to the suburbs.There was a large Jewish community but this has now dwindled.
A great number of people in this area are either of Asian or West Indian origin.With the boom in "fast-food" a lot of supposedly "traditional cockney food went into decline.
The only items i can think of are: Pie & mash,seafoods e.g. cockles,whelks,winkles and jellied eels. "Cockney"cookery is inaccurate as the area has always been cosmopolitan.
I wish i could be more helpful with your request,Leo.