- Place juice in a small saucepan over medium-high heat and simmer until reduced to about 3 tablespoons and liquid is a thick syrup. Set aside. When cool, add remaining dressing ingredients, from vinegar to salt and pepper. Whip. Set aside for flavors to blend.
- Place spinach in a large serving bowl. Top with onion, watermelon, raspberries, and pomegranate seeds. Divide onto 4 salad places and drizzle with dressing.