Grapefruit-Blackberry Dressing

1/4 cup olive oil
1/ cup fresh-squeezed grapefruit juice
1/4 cup whole-fruit blackberry preserves
Arugula leaves
1 mango
Blackberries
1 grapefruit, sectioned

Whisk together olive oil, fresh-squeezed grapefruit juice, and blackberry preserves; serve over a salad of arugula leaves, mango and jicama cubes, blackberries, and grapefruit sections