Remove stems from kale & wash; pat dry on paper towels. Set aside. Remove roots, tough outer leaves & tops from leeks. Split leeks in half lengthwise. Place leeks in a small dutch oven & cook, covered, in a small amount of boiling water about 5 min. Or till tender. Remove with a slotted spoon; cut leeks into julienne strips & set aside. Return liquid to a boil; add carrots. Cover & cook 1 min; remove with a slotted spoon. Add kale, cover & cook 1 min. Drain. Line a serving platter with cooked kale. Arrange leeks & carrots in individual servings on top of kale. Cover & chill. Combine green onions, yogurt, garlic, salt, pepper & vinegar in a small bowl. Stir well. Cover & chill. Serve yogurt with salad.