In 2-quart saucepan, combine 3 cups cold water, sugar and cinnamon stick. Bring
to a boil and add cherries. Partially cover and simmer 35 to 40 minutes if cherries
are fresh — 10 minutes if canned.
Remove cinnamon stick. Mix arrowroot and 2 tablespoons cold water into a paste.
Beat paste into soup, stirring constantly. Bring soup almost to a boil. Reduce heat
and simmer until clear and slightly thickened, about 2 minutes.