In a small bowl, add the Hidden Valley® Original Ranch® Dressing, mustard, honey, and vinegar, and stir until well blended. Chill covered until ready to serve. In a large bowl, toss the beets, oranges, chicken, and onion, and toss until well coated. Divide the spinach leaves evenly among 4 salad plates. Top each serving with even amounts of the beet mixture and serve garnished with the seeds.