Place all ingredients for the dressing in a Mason jar and shake well; refrigerate for 1 hour before serving.
Place greens on a large platter; top with onion, cucumber, bacon, watermelon and Parmesan; garnish with flowers. Serve the green herb dressing on the side—and let everyone add to taste.
Quick Tip: This recipe makes 4 cups (1 L) of Green Herb Dressing, which will keep for up to 2 weeks in the refrigerator.