Preparation:

1. Make the Basil Pesto, up to a week in advance. Store covered with a layer of olive oil in the refrigerator.
2. Slice the salmon fillets on the diagonal into 1/2" slices. There should be about 8 slices. Arrange the slices in a single layer on a plate. Sprinkle with the lemon juice, salt and pepper. Cover and refrigerate for 4 to 24 hours.
3. Place the salmon in a deep large skillet. Heat salted water to boiling. Ladle the water into the skillet and place over low heat. Poach the fish until almost, but not quite, cooked through, about 4 minutes. Remove with a slotted spoon to paper towel to drain.
4. Heat a large pot of salted water to boiling. Stir in the haricots verts or thin green beans; cover the pot just until the water returns to a boil. Cook just until the beans are tender, about 2 minutes. Remove with a slotted spoon to a colander to drain.
5. Let the water return to a boil. Stir in the potato slices. Cook, stirring gently to separate, until the potatoes are tender, but still have some bite, about 3 minutes. Drain the potatoes in a colander, shaking gently to drain as much liquid as possible from them. Slide the potatoes into a mixing bowl, drizzle with the olive oil and sprinkle generously with salt and pepper. Toss gently to coat the potatoes with the seasoned oil.
6. Divide the potatoes among the serving plates. Scatter the beans over the potatoes and top with slices of salmon. Just before serving, drizzle with the pesto.
Per Serving: 460 Calories; 29g Fat (4g Sat, 19g Mono, 4g Poly); 23g Protein; 26g Carbohydrate; 3g Dietary Fiber; 46mg Cholesterol; 648mg Sodium.  Food Exchanges: 3 Lean Meat; 1/2 Vegetable; 5 Fat.
Cooks Note: The salad can be prepared through step 2 up to a day ahead. Prepare through step 5 no longer than 2 hours before serving. Leave all the ingredients at room temperature, tossing the potatoes, once or twice. Bring the pesto to room temperature.  Assemble the salad and drizzle with pesto just before serving.