In this main-course riff on salade niçoise, the olives make a splash in the dressing while peppery arugula stands in for lettuce, grilled salmon for oil-packed tuna. Yet the beautiful contrasts of the original are still front and center: potatoes, green beans, tomatoes, and hard-boiled eggs.
03Cover potatoes with water in a 4-quart pot and season well with salt. Bring to a boil, then reduce heat and simmer, uncovered, until just tender, 15 to 20 minutes.
04While potatoes cook, season salmon with 1/2 teaspoon salt and 1/4 teaspoon pepper. Oil grill rack, then grill salmon, covered, turning once, until just cooked through, 8 to 10 minutes total. Cool slightly, then gently break into large flakes. If desired, reserve skin for crumbling over salad.
05Transfer potatoes with a slotted spoon to a bowl. Add green beans to boiling water and cook, uncovered, until crisp-tender, 4 to 5 minutes. Drain and transfer to an ice bath to stop cooking.
06Halve potatoes while still warm and toss with 2 tablespoons dressing.
07Toss green beans, cherry tomatoes, and arugula with enough dressing to coat, then toss with potatoes. Divide among plates with salmon and eggs. Sprinkle with basil (and salmon skin, if using). Serve with lemon wedges and remaining dressing.