In this classic dish, which takes its namefromNice, in Provence, the seasonal ingredients create a wonderful explosion offlavors.
Bring the potatoes to a boil in a largesaucepan of water. Add salt; reduce heat,and simmer until tender, 10 to 15 minutes. Drain; let cool slightly.
Cut the potatoes into bite-size pieces;peelany loose skins. Dress with enoughvinaigrette to coat lightly (reserve remainder). Season with salt and pepper.Set potatoes aside.
Prepare an ice-water bath; set aside.Cover eggs with water in a small saucepan; bring to a full boil. After 1 minute,cover and turn off heat. Let stand 6 minutes. Rinse; transfer to ice-water bath.
Prepare another ice-water bath; setaside. Bring a medium saucepan of waterto a boil; add salt. Blanch green beansuntil crisp-tender, 1 to 2 minutes. Drain;rinse with cold water. Let stand in ice-water bath until cool. Drain; pat dry.
Peel the eggs, and halve lengthwise.Arrange lettuce, then potatoes, greenbeans, bell pepper, tomatoes, cucumber,fennel, tuna, eggs, and olives on a platter.
Sprinkle with scallion and parsley,and with capers if desired. Drizzle withvinaigrette, and serve with remainder.