Cut goat cheese into 4 equal portions and reserve.
Divide the frisee among 4 plates. Scatter the cucumber, chives, tomatoes, nuts, onions and tarragon equally among the portions of lettuce. Crumble a 2-ounce portion of cheese over each salad.
Place shallot in a small bowl with vinegar and lemon juice. Let vinegar stand 5 to 10 minutes. Whisk in extra-virgin olive oil in a slow stream. Drizzle dressing over each salad, then season with salt and pepper.