Make this at the height of summer when the beans are sweet and the tomatoes juicy. This is a great dish to feed a crowd, not only because you can prep the ingredients beforehand, but also because guests can compose individual salads according to their preferences. Think of this recipe as a blueprint and change it as you wish, subbing canned tuna for fresh, doubling or omitting the anchovies, adding salad greens, radishes, etc. If there are leftovers, toss all the ingredients together for a terrific next-day lunch. If grilling fresh tuna, err on the side of medium or medium-rare; tuna cooked all the way the way through is tough and not as flavorful.

Steps

1. Bring a large pot of salted water to a boil. Add the green beans, turn down to a simmer, and cook until tender, about 5 to 10 minutes. Scoop beans out of pot with a slotted spoon and run under cold water to stop the cooking. Drain and set aside.
2. Return the pot of water to a boil and add the potatoes. Turn down to a simmer, partially cover, and cook until potatoes are tender, about 10 to 20 minutes. Drain and cool.
3. Meanwhile, prepare the vinaigrette. In a suribachi or mortar and pestle, pound garlic and salt into a paste (alternatively, place minced garlic and salt in a small bowl). Add mustard and vinegar and whisk until smooth. Slowly drizzle in olive oil, whisking all the while, to emulsify the vinaigrette. Stir in chopped basil.
4. To make the salad, start by slicing the cooked potatoes into wedges. Place in a medium bowl, toss with half the vinaigrette, and season to taste with salt and pepper. In another bowl, toss the cooked green beans with a quarter of the dressing.
5. There are two ways to compose this salad: Either place individual ingredients in separate bowls on the table, or arrange all the ingredients on a large platter. If opting for the large platter, place dressed potatoes on a section of the platter, then set dressed green beans next to the potatoes. Add sliced tomatoes, tuna (broken into chunks) and hard-boiled eggs. Scatter olives over the salad. Drizzle remaining vinaigrette over the tomatoes and tuna. Drape anchovies over the eggs and/or other ingredients. Season to taste with salt and lots of freshly ground black pepper.