Heirloom Herb. Chervil seeds produce a plant with aromatic, finely cut, bright green leaves are used in salads and seasoning. Chervil is used in the ‘fines herbes’ mixture made famous by French cuisine. When chervil is used alone it is best with cold dishes or just prior to presentation of cooked foods. In the garden, chervil is sometimes used as a decoy plant for slugs and other garden pests. Chervil may grow adventively where sun exposure and moisture conditions are relatively constant year-over-year.  Annual.