In a sauce pan, place the fruit, sugar, and lemon juice. Simmer for 10 minutes or until fruit is very soft.
Dissolve the cornstarch in the water.
Add dissolved cornstarch to the fruit. Allow to simmer, stirring frequently for 10 minutes. Mixture should thicken.
If you'd like a smoother flavoring, allow the mixture to cool, then run it through a blender until you reach the desired texture.
Add to your yogurt and enjoy!