Peel and slice the onion into paper thin rounds. The easiest way to do this is with a mandoline slicer. if you don't have one, just get them as thin as you can. Separate the rings.

Put the dressing at the bottom of a very large salad bowl.

Put the greens and onions into the bowl, but don't mix with the dressing.

Scatter the edible flowers across the top of the salad.

Bring the salad to the table and toss with the dressing just before serving.

Alternately you can serve the dressing on the side.