Soak clay oven in water to cover 10 minutes.
Place lemon in chicken cavity. Tuck wings under, and tie legs together with string, if desired. Place chicken in clay pot, breast side up, and sprinkle with tarragon. Cover with lid.
Place in cold oven. Turn oven to 450°, and bake 1 hour. Uncover and bake 15 more minutes or until a meat thermometer inserted into chicken thigh registers 180°.