Frisee Salad with Pistachios and Dijon Vinaigrette

12 ounces frisee (1 to 2 bunches), stems trimmed, leaves torn into 3-inch pieces (about 15 cups)

1/2 small head radicchio, preferably Treviso, cored and thinly sliced (about 3 cups)

2 tablespoons fresh tarragon leaves, plus tarragon flowers (optional)

2 teaspoons Dijon mustard

1 tablespoon fresh lemon juice

1/4 teaspoon sugar

1/4 cup extra-virgin olive oil

Coarse salt and freshly ground pepper

1/2 cup shelled raw pistachios

Combine frisee, radicchio, and tarragon leaves in a serving bowl.  In a small bowl, whisk together mustard, lemon juice and sugar.  Slowly whisk in oil; season with salt and pepper.  Dizzle dressing over salad, tossing to coat. Sprinkle with pistachios and tarragon flowers and serve.

Serves 8.