Tarragon Leaves. Vive le Tarragon! A key ingredient in French cuisine, Tarragon is known in France as the “King of Herbs”. Tarragon leaves grow on a small herb plant and, when dried, retain their vivid dark green colour. They have a warm, minty anise-like aroma and tart flavour. Tarragon marries well with meat and fish and is used to make the popular béarnaise sauce. It enhances the flavour of many foods, though it can become overpowering if used excessively.