Bitter greens (escarole, watercress, and raddichio) are tossed with citrus and kumquat slices. The dressing, a simple mixture of fresh orange juice, zest, champagne vinegar, and light olive oil, and blood oranges and clementines add just a bit of sweetness to help balance the flavors.
Prepare Salad: Trim the ends of the clementines, blood oranges, and grapefruit. Using a knife, remove the peel and all of the white pith from the sides. Cut the citrus into ¼-inch rounds–removing any seeds as you work. Cut the grapefruit rounds into half-moons. Set aside.
Sort through the watercress–keeping any small stems, and removing the leaves from the tougher stems. Trim the base of the raddichio and tear the tears into small strands. Remove the outer, tougher leaves of the escarole and base, and tear into large pieces. Wash and dry the leaves in a salad spinner thoroughly. Place in a large Ziploc bag and refrigerate until needed.
Prepare Dressing:Whisk together the orange zest, orange juice, champagne vinegar, and salt in a bowl. Slowly drizzle in the olive oil, whisking continuously to emulsify.
Add the sliced kumquats to the dressing and allow them to sit for 5 to 10 minutes (this will remove some of the bitterness).
Dress the salad leaves lightly (reserving the kumquat slices as a garnish) with the dressing. Season to taste. Top with the various citrus slices and kumquat slices. Serve immediately.