Season salmon fillet with ¼ teaspoon kosher salt and ¼ teaspoon freshly ground black pepper.
Heat olive oil in a medium-sized non-stick skillet over medium-high heat.
Add salmon flesh-side down (skin-side up) to the skillet. Cook for 2-3 minutes, until the flesh side has a nice golden crust.
Flip the salmon over, and transfer to a baking dish or small sheet pan lined with foil. Put into the oven for 8-10 minutes, until it flakes easily with a fork and reaches 125-130°F for medium-rare. Remove from oven and let it rest until salad is ready to assemble.
Meanwhile, bring a medium-large saucepan of water to a boil.
Rinse green beans, and trim the stems.
Rinse potatoes, scrubbing off any dirt.
Slice cherry tomatoes in half.
Peel and slice or quarter hard-boiled eggs.
Boil potatoes for 10-15 minutes, until tender, then remove with a slotted spoon into a colander. Rinse under cold water. Let potatoes cool slightly, then slice or quarter.
Add the green beans to the same pot. After 5 minutes, drain in the colander and rinse under cold water.
While the vegetables are cooking, make the vinaigrette. Chop anchovy into a paste and mince shallot.
Add to a bowl, then whisk in champagne vinegar, Dijon mustard, and Herbes de Provence.
Slowly whisk in olive oil until dressing emulsifies. Whisk in salt and pepper, taste, and add more seasoning if necessary.
To assemble the salad, break the salmon into large chunks. Then arrange green beans, sliced potatoes, sliced eggs, salmon, cherry tomatoes, Nicoise olives, and 8 anchovies (optional) each in their own section on a large platter, and have diners help themselves. Or, plate individual servings with a little of each.
Drizzle with the vinaigrette and serve.
Notes
Expert Tips: If you don’t want to pre-sear the salmon before putting it in the oven, you can also broil it. Bake the salmon as directed in the oven, but then move under the broiler for the last minute or two in order to brown the top. Just make sure you are using a broiler-safe sheet pan that is lined with foil rather than parchment paper.Need a foolproof way to hard-boil your eggs? Here's the Cook’s Illustrated method: Add eggs to a saucepan, then cover the eggs with about an inch of water. Turn the heat to high and bring to a full boil, then take the pan off the heat, cover, and let it sit for 10 minutes. Move the eggs to an ice bath for 5 minutes, then peel. Or use the egg cooker above! Pat the salmon fillet dry before seasoning. If you put a damp fillet into your pan, it will steam rather than brown. Storage Tips: Store each component separately in airtight containers in the refrigerator. The cooked salmon will keep 2-3 days in the refrigerator, while the potatoes and green beans will keep for 4-5 days. The hard-boiled eggs will last for about 3 days. The cherry tomatoes will keep for 2 days in the fridge, but will lose some of their flavor once refrigerated.Store any extra vinaigrette in a jar with a lid in the refrigerator. It will keep for at least a week, if not two. Whisk or shake it up before using.