Endive boats with avocado, pomegranate, & crab salad gluten

Ingredients

For the Pomegranate Sauce:

• 3 egg yolks
• 1/4 cup dashi (or vegetable stock)
• 4 teaspoons rice vinegar
• 2 tablespoons pomegranate juice concentrate
• 1 tablespoon granulated sugar
• 1 teaspoon soy sauce
• 2 medium, ripe avocados cut into 1/4-inch cubes
• 6 ounces cooked crab meat
• 3/4 cup pomegranate arils
• 2 large heads Belgian endive
• Finely grated lemon zest, to garnish