Drain the cracked wheat and put in a large bowl. Cook the barley and wheat berries according to package directions in separate pots until soft, but still firm. Soak the sumac in 2 teaspoons of water. Strain the sumac, barley and wheat berries. Add them to the large bowl. Add remaining ingredients, except pine nuts, to the bowl and mix gently. Adjust seasoning and salt, to taste. Keep the salad at room temperature for 1 hour before serving. Serve in 4 individual bowls and garnish with pine nuts.