Arrowroot is a starch in the form of a fine, white, flavourless powder which is extracted from the rhizomes of several tropical plants, including maranta. It is used to thicken sauces and soups and has a reputation for digestibility which has resulted in its use in the preparation of gruels and foods for convalescents. It provides a clear, glossy finish to dishes. Arrowroot loses its thickening powers if it is overcooked. Historically it was used for treatment of arrow wounds. When adding Arrowroot
To use, mix it to a paste with a little water, add to the sauce and heat gently until glossy and thick. Don't overcook or it may go thin again.