In large bowl, combine all salad ingredients except onion top and reserved orange segments; mix well. In small bowl, combine all dressing ingredients; blend well.
Add dressing to salad; toss to coat. Serve immediately, or cover and refrigerate until serving time.
To make flower garnish, cut lengthwise slits, 2/3 of the way down, in reserved green onion top; curve strips to resemble leaves. Arrange reserved mandarin orange segments on top of leaves to resemble flower petals.