How to Make It
In a blender, combine the parsley, scallion, tarragon, vegetable oil, white wine vinegar and water and puree. Season the vinaigrette with salt and pepper.
On 2 plates, decoratively stack the Boston lettuce leaves to form a flower shape, using the largest leaves on the bottom and working up to the smallest leaves. Drizzle the salads with the vinaigrette, garnish with the herb sprigs and serve.