A question about a recipe: Salmon in Sorrel Sauce

Chervil is a very "green" herb, which tastes somewhat like parsley mixed with a little tarragon. It's got frond-y leaves, and can be often be found in farmers markets (in season) and in specialty grocery stores that have a well-stocked herb section. If you can't find it, substitute parsley.

Here's a link: http://www.herbcompanion.com/cooking/chervil-fine-herbe-for-kitchen.aspx