1/4 cup Dijon mustard
Juice of 2 lemons
3 tablespoons white wine vinegar
2 shallots, pasted
2 large cloves garlic, pasted
1 tablespoon dried tarragon or 1/4 cup chopped fresh
1 teaspoon fennel pollen or ground fennel
1 cup EVOO
Salt and pepper
1 to 1 1/2 pounds potatoes (about 2 large), diced
1 or 2 ribs celery, finely chopped
1/4 red onion, finely chopped
1/3 to 1/2 pound haricots verts (very thin green beans)
1/2 pound baby heirloom tomatoes, halved
10 or so fresh basil leaves, coarsely chopped
1/2 seedless cucumber, very thinly sliced
2 (6-ounce) cans line-caught tuna, drained
1/4 cup capers
1 shallot, sliced into very thin rings
1/2 cup thinly sliced radishes
4 hard-boiled eggs, peeled
12 good-quality anchovy fillets
2 handfuls of Niçoise olives
Make the vinaigrette: In a small bowl, whisk together all the ingredients.
Make the salad: In a saucepan of boiling water, cook the potatoes until tender. Drain and let cool, then transfer to a bowl. Add the celery and onion. In a separate saucepan of boiling salted water, cook the beans 3 to 4 minutes, then drain and cold-shock to stop the cooking. In a small bowl, toss the tomatoes with the basil.
Add enough vinaigrette to the potatoes to just coat, and toss together. Transfer the potatoes to one end of a platter. Put the beans in the same bowl and toss with a little more vinaigrette. Arrange on the platter in a strip next to the potatoes. Again in the same bowl, toss the cucumbers with some vinaigrette and put those on the platter.
Arrange the tuna in big chunks on the platter and top with the capers and shallot rings. Arrange the radishes, tomato mixture, eggs, anchovies, and olives in strips on the platter. Drizzle the remainder of the vinaigrette down over the things that were not tossed with it. That way certain things are not overdressed and certain things are not underdressed.