Nouveau Nicoise

Bring water to a boil in a 3- to 4-quart saucepan. Add green beans and cook until just tender and bright green, 1 to 2 minutes. Using a slotted spoon, transfer the beans to a colander, rinse under cold water and set aside in a large bowl. Carefully place potatoes and eggs into the boiling water. Cook the eggs until hard, 12 minutes. Using a slotted spoon, transfer the eggs to the colander, rinse under cold water until cool and set aside. Continue cooking the potatoes until fork-tender, 3 minutes more. Drain the potatoes; rinse under cold water until cool enough to handle. Meanwhile, combine shallots, vinegar, mustard, salt and pepper in a small bowl. Slowly whisk in oil. Cut the potatoes into quarters or eighths, depending on their size. Add to the bowl with the beans. Add greens, tuna and the dressing. Toss well. Peel the eggs and cut into wedges. Divide the salad among 4 plates. Top with egg wedges and olives. Serve immediately.