A key ingredient in classic French cuisine, tarragon has a distinctive taste that's hard to accurately substitute. The aniselike flavor of tarragon complements fish, eggs, chicken and some types of cheese. French chefs often use fresh tarragon in sauces like bearnaise or in its dried form in herbal blends such as fines herbes. Other herbs can replace tarragon in a pinch.
Basil, a staple in Mediterranean and Southeast Asian cooking, is used in pesto sauces, pasta sauces, seafood and stir-fries. Basil has a flavor somewhat similar to tarragon and it is generally easier to find. Substitute basil for tarragon in French or Italian sauces. Basil can also replace tarragon in seafood or pasta dishes and in some salads and dressings.
Marjoram has a taste reminiscent of oregano in many ways. This herb is best when used toward the end of the cooking process because its flavor fades quickly when exposed to high heat. Both marjoram and tarragon are commonly used in fish dishes. You can use marjoram in place of tarragon when you cook a whole fish. Cut and clean the center of the fish, stuff it with fresh marjoram and other herbs and roast the whole fish.
Fennel is a leafy green vegetable that has numerous uses and its seeds are used as a spice. Fennel seeds have a strong anise flavor which makes them a useful flavor substitute for tarragon. Fennel seeds taste best when they're toasted and freshly ground just before cooking. You can use fennel seeds in place of tarragon for fish and salads, with cheeses and in fish and meat marinades.
Anise is the flavor most commonly associated with liquorice. Many people describe tarragon as having a mild anise flavor. Because of this, anise is a good substitute for tarragon. Ground anise works well with cheeses, eggs, fish, in soups and as an aromatic enhancer in stocks and sauces. Try using ground anise the next time a recipe calls for tarragon. Start with a tiny amount of anise and add it gradually because its flavor is much stronger than tarragon.