In a jar or dressing shaker, mix together the vinegar, honey, onion, Dijon mustard, salt, poppy seeds and oil. Cover and shake until well blended.
Toss all of the salad ingredients together in a large bowl. Drizzle a little of the dressing over the greens and toss gently to coat. Continue adding the dressing and gently toss until all ingredients are evenly coated.
The dressing can be made up to two days ahead of time and stored in a sealed container in the refrigerator.