1 medium watermelon
1 cup mascarpone cheese
1 orange, zested and segmented — juices set aside
2 lemons, zested and segmented — juices set aside
1 grapefruit, zested and segmented — juices set aside
2 tablespoons sugar
Cut watermelon in half lengthwise. Using a melon baller, cut into balls and place in a shallow serving bowl.
In a blender, mix the mascarpone and the citrus fruit juices and the sugar until smooth. If too thick, thin with a little water (it should be as thick as yogurt). Drizzle the mascarpone over the watermelon balls and sprinkle the fruit segments over and serve cool.