A real Salade Nicoise is a vegetable salad with tuna, anchovies, tomatoes, green peppers and olives. What a restaurant in the south of France does is cook extra vegetables like new potatoes and green beans to serve in the salad the next day. You can do that too! Nowadays, lots of cooks are making variations; for instance, using grilled fresh tuna instead of canned tuna, or grilled salmon. Either way, it is a great summer luncheon or supper main course. Just serve it with a glass of white wine, a chunk of cheese, and a loaf of crusty bread.
To make the vinaigrette, combine in a pitcher and blend well the vinegar, oil, mustard, capers, parsley, with salt and pepper to taste.
Wash and dry the lettuce leaves and toss with some of the vinaigrette. Arrange around the edges of a large salad bowl. Separately, toss the potatoes and green beans in the vinaigrette, as well. Add to the middle of the bowl. In the center of that, put the tuna, in chunks. Season with salt and pepper. Decorate with the tomatoes, eggs, onion and pepper rings, and olives. Also, decorate with the anchovies, if desired.
Although Salade Nicoise is traditionally made with canned tuna fish, I sometimes make it with salmon or fresh tuna that has been seasoned well with salt and pepper and broiled or grilled for 10 minutes.
You can make the salad ahead if you do not dress it until the time you serve it.