2 pounds medium potatoes, like Yukon Gold or Yellow Finn
Salt and pepper
1 bay leaf
1 large thyme sprig
3 garlic cloves, smashed to a paste with a little salt
1 tablespoon chopped anchovy
1 tablespoon chopped capers
2 teaspoons Dijon mustard
4 tablespoons white wine vinegar
⅓ cup extra virgin olive oil
1 pound small French beans, or small romano or wax beans
4 large eggs
1 tablespoon thinly sliced chives
2 tablespoons roughly chopped parsley
2 tablespoons roughly chopped basil
6 to 8 anchovy fillets, optional, for garnish
8 ounces arugula, optional
Bring a large pot of well-salted water to a boil. Add the potatoes, bay leaf and thyme branch. Cook at a brisk simmer until the potatoes are firm but easily pierced with a skewer, about 30 minutes. Remove and let cool slightly.
While the potatoes are cooking, make the vinaigrette: In a small bowl, stir together the garlic, anchovy, capers, mustard and vinegar. Slowly whisk in the olive oil. Season to taste with salt and pepper. Whisk again before using if the dressing separates.
When the potatoes are cool enough to handle, remove the skins with a paring knife and carefully cut into pieces 1/4-inch thick, or slightly thicker. Put the slices in a low bowl, season lightly with salt and pepper and add half the vinaigrette. Using your hands, gently coat the potatoes with the vinaigrette, taking care not to break them. Cover and set aside at room temperature.
Top and tail the beans. Simmer in salted water until firm-tender, about 3 to 4 minutes, then cool under running water and pat dry.
To cook the eggs, bring a medium pot of water to a rapid boil. Add the eggs and cook for 8 minutes for a somewhat soft-centered yolk or 9 minutes for a firmer yolk. Cool the eggs immediately in ice water, then crack and peel. Cut each egg in half and season lightly with salt and pepper.
When ready to serve, season the beans with salt and pepper, then dress with the remaining vinaigrette. (Reserve 2 tablespoons vinaigrette for the arugula, if using.)
Combine the dressed beans and potatoes, using hands to toss, and pile onto a platter. Sprinkle with chives, parsley and basil and arrange the eggs over the top. Garnish with anchovy fillets, if desired. Dress the arugula and send it to the table separately.