This soup should be made with spring vegetables. Take some carrots and turnips, wash them well and scrape them lightly, also a white cabbage. Remove the outside leaves and use the heart only. Cut this and the other vegetables in thin pieces, together with the white of two leeks, and cook slowly in butter in a saucepan, keeping the lid on all the time. When tender, add the heart of a lettuce cut in four, a handful of fresh peas and a little chopped chervil, then consommé or stock. You should add consommé in sufficient quantity so that you have enough for your purpose when it has reduced by one-third, as it should do, on a slow fire. See that it is properly seasoned and, just before serving, add the yolk of one egg diluted in a little cream and well beaten, and mix it well with this pleasing mixture of spring vegetables.