It's a classic preparation that is available at just about…
Traditionally, a salad such as Niçoise, of course named for Nice, France, is considered a composed hors-d’oeuvre. According to culinary classicists like Elizabeth David and Escoffier, it contains elements of raw, salt, smooth and subtle, crisp, dry, meaty and sometimes often fish. Those are all very good things to eat.
The ingredients would be seasonal, but hard-boiled eggs are important as are anchovy, black olives, chervil, tomatoes and garlic in the dressing. Green beans often find their way into the hors-d’oeuvre, as do potatoes, making the dish somewhat country-rustic at the same time it is composed.
In this version, I added a few pieces of an orange pepper that I had in the fridge, and I blanched the beans but kept them quite crisp.
I had no chervil — I mean, who does? — and so I dropped loads of tarragon (and I was lucky to have that) into the oil and mustard emulsion along with some finely minced (almost paste-like) white onion and a couple of tablespoons of apple cider vinegar.
As for the fish, I poached for mere seconds a couple of thin pieces of trout — which substituted for the tuna that I would have liked to have just seared on the outside leaving a ribbon of pink in the middle.