Taking a handful of parsley and one of chervil, and some leaves of tarragon, scald with hot water, put into a mortar ; do the same with a few leaves of spinach, add two gherkins and two spoonfuls of capers; pound all together with a piece of fresh butter, then pass the whole through a fine sieve; mix this into white bechamel (see 'Dainty Dishes') sauce at the last moment. Stir and warm up - must not boil. Pour this over the vegetable the moment before serving. Boiled fish, poached eggs, turnips, carrots, branches of seakale, beet, oxalis, Jerusalem artichokes, celeriac, waxy potatoes, are all good with this sauce.