Combine the mango, red pepper and cabbage in a large bowl. Blend tahini, orange juice, maple syrup, lime juice, tamari, ginger, chili and oil. Pour blended mixture on mango, pepper and cabbage. Mix well.Cut center rib out of each blanched collard green leaf. Set 1/2 of leaf on a flat surface, underside facing up, cut side towards you. Spoon a few tablespoons of the fruit and vegetable mixture onto the leaf, filling all but the bottom 1 1/2 inches. Top the fruit and vegetables with a small amount of watercress and sprinkle with hemp seeds. Fold the bottom of the leaf up, keep it tight and continue folding it up to make a nice wrap. Set wrap seam-side down on a platter and garnish with chopped cilantro. Follow the same directions for the remaining leaves, and serve immediately or chill.