Toss the potatoes with 1 tablespoon of the olive oil, 1/2 teaspoon salt and a few grinds of pepper on a baking sheet. Roast for 15 minutes.
Meanwhile, toss the haricot verts with 1 tablespoon olive oil, 1/4 teaspoon salt and a few grinds of pepper and place on one side of a second baking sheet. Place the eggs on the other side of the baking sheet. After the potatoes have roasted for 15 minutes, add the second baking sheet to the oven. Continue to roast until the potatoes are golden brown and crispy in spots and easily pierced with a fork and the green beans are tender and crisp in spots, about 15 minutes more.
Immediately submerge the eggs into a bowl of ice water and let sit for 10 minutes. Peel and quarter the eggs.
Mix the vinegar, mustard, thyme leaves and red onion in a medium bowl. Whisking constantly, drizzle in the remaining 1/4 cup olive oil until emulsified.
Divide the lettuce among serving plates. Arrange the potatoes, haricot verts, salmon, eggs, cherry tomatoes and olives on top of the lettuce and drizzle each plate with some of the dressing. Sprinkle with salt and a few grinds of black pepper.