I love to make a somewhat composed nicoise salad on a generous platter when entertaining in the heat of summer. The only things that need to be cooked are the eggs, potatoes and green beans and the vegetables can be done in the same pot.
Start with potatoes in cold salted water and bring to a boil. When they are tender, add the green beans and cook until they reach the point where they are not simply hot but just cooked. Drain, rinse with cold water and separate them. For the potatoes, you can peel them if you like, slice them and then dress them with some dijon vinaigrette while they are still warm so the absorb the dressing. You can dress the green beans as well.
If you love anchovies, you can add some to your dressing and/or slice them and garnish the salad with them.
Halve cherry tomatoes and season them with salt and pepper.
Make hard boiled eggs and peel, quarter and season them.
You can arrange the components (the tuna, tomatoes, potatoes, green beans, eggs) of the salad in loose sections directly on a platter or over lettuce or arugula. Basil and parsley are nice on top as well. Sometimes I add sliced red onions. And of course a scattering of nicoise olives over it all.
Growing up, my mom often swapped the potatoes for pasta and made a tuna nicoise pasta salad with tuna, cherry tomatoes, basil, red onion, green beans, olives, anchovies and a dijon vinaigrette.