Bring the water to a boil in a medium saucepan. Stir in rhubarb, strawberries, sugar, and cinnamon. Boil 3 minutes, stirring occasionally.

Reduce heat and simmer 10 minutes, stirring occasionally.

Let stand until cool.

Combine strawberry-rhubarb mixture and yogurt in a blender and process until smooth. Chill until ready to serve.

Garnish with fresh whipped cream, sour cream, and/or fresh strawberries.

(*Recipe adapted from An Occasion To Gather: Summer Blueberry Soup)