Basically, instead of tinned tuna I used tinned mackerel. It makes a lighter dish that's slightly less sweet. Then other changes appeared.
This Nicoise salad is courtesy my usual style of random crisper box cooking, what my daughter has affectionately dubbed "chickpeas and groceries." The Nicoise elements are potatoes, green beans, hard boiled egg, tinned fish. To that I slipped in sliced radishes, parsley, capers and a couple anchovies. Black pepper, salt and some olive oil, too. No olives, no lettuce. And I mix it all in a jumbled mess which makes it more like a potato salad Nicoise, not the picture-perfect composed salad you usually see.
Nicoise salads — like most salads — are trickier than they seem. Besides starting with good ingredients there are a few techniques that keep it away from bland-dom.
Potatoes: cook them whole, in their jackets, in very salty water. Cool them in the water, then undress them. Slip the peel off with your fingers or the edge of a paring knife. Chop into odd sized chunks.
Tinned fish: dump in the whole tin, olive oil and all. Don't skimp on the quality of the fish. This is one place you'll really taste the difference.
Green beans: barely blanch in very salty water, then chill quickly in a bowl of ice water. Dry them off.
Egg: cook it on the softer side of hard, then chop it to bits so it emulsifies a bit with the olive oil.
Olive oil: add a lot of a tasty one. This one is from Nice if that helps.
Mix: with your hands. This is my advice on mixing nearly every salad. Hand mixing lets you know when all the parts are coated. It gets the salad to be dressed more homogenously. When it's ready to eat it's not pretty (like the picture above), but it's very tasty: