2 pink or red grapefruits
2 small young fennel bulbs (halved, cored, and sliced paper-thin crosswise)
1/2 small jicama (peeled and cut into 1/4-inch-thick matchsticks, about 1 cup)
4 ounces Earthbound Farm Organic Baby Arugula
  Fennel fronds (for garnish, optional)
1/4 cup extra-virgin olive oil
1/4 cup grapefruit juice
1 tablespoon fresh lemon juice (or more to taste)
  Sea salt
  Freshly ground black pepper