Not sure where in East London you are but I've been out with a friend from Ilford a couple of times and there are some lovely quiet lanes around Abridge/Ongar, all not a million miles from Epping.
based in south woodford, originally from Ilford myself, as for surrounding area really don't know it that well to ride, most of my friends i ride with are MTB riders, so we do trails in and around chingford right out to epping, I would just love to grab my cx hybrid and pootle out on the quiet country roads, as I have never tried that.