I was always taught to refresh leeks in cold water for this dish. I now think differently. It may make the green part of the leek greener, but you lose much of the flavour into the water while they cool. I sometimes think we do too much blanching, with vegetables here, there and everywhere being flung into iced water to set the colour and arrest the cooking; it all gets a bit cosmetic.
It is easier to make a large quantity of this dressing than a small one. It can be stored in the f