Sunny Springtime Luncheon Salad

Fiddleheads, golden squash, little potatoes, eggs, and cress in dill-mustard sauce make a pretty picture. The bouquet of rounds upon rounds—yellow, green, and white—tastes best lukewarm or at room temperature. The appealing textures change if chilled—and the pistachio ferns turn sickly green if dressed in advance. For a meaty meal, serve thin slices of ham alongside.