Approximately 4 c. cut rhubarb or sour cherries, pitted
1 c. sugar
1/4 c. cornstarch

Prepare fruit and place in saucepan. Barely cover with water. Simmer until very soft, strain out juice. Mix 1 cup sugar and cornstarch. Add to 2 cups of strained juice and cook until thick, stirring constantly. Let cool. Serve with whipped cream.