Here is a dish that would have pleased the French gourmets of the Renaissance, for at that time the tender asparagus was a culinary novelty. Since then, the appearance of fresh asparagus on our tables announces that spring is here. Seventeenth-century cooks recommended that asparagus be eaten slightly crunchy - al dente, as the Italians say. Later, it was preferred soft, with a longer cooking time. Whether you like it, as Marcel Proust did, with a mousseline sauce, or prefer hollandaise or vinaigrette, it is among the finest vegetables in French cooking.