Put the herbs into a stewpan with cold water to cover.
Add the peeled eschalot and a tiny bit of soda.
Original Text
Verte Sauce.—Take two or three good sprigs of parsley, tarragon, chervil, and also one of fennel if you can get it, wash them well and put them into a stewpan with cold water to cover, add one small peeled eschalot and a tiny bit of soda,