I recently finally went and found a Russian supermarket, which had been recommended to me by a colleague a while back, and sells a decent array of foods from former USSR countries. Unfortunately it doesn't have some of the things I'd most like, like Sulguni cheese, but it does have a comparatively very reasonably priced Georgian wine selection and some mini khinkali which turned out more edible than I'd expected (though one can't eat them in the proper way for khinkali, they're too small to hold by the twist of the dough).