In an enamel or stainless steel saucepan soak the fruit in the water for 1 1/2 hours. Add the sugar, lemon juice, and cinnamon stick, bring the liquid to a boil, and simmer it until the fruit is tender, for 15-20 minutes. Stir in the arrowroot paste and heat until the soup is thickened, for about 1 minute. Chill the soup. Remove the cinnamon stick and serve with a pitcher of cream. Garnish with mint leaves.