Pasta with Mustard-Green Pesto, Walnuts, and Raisins

A curious and delicious dish for lovers of bitter greens. The mustard leaves, sprinkled with boiling water and pureed, keep their strong herbal scent and sharp flavor—which are then reinforced by the raw mustard filaments. Curly egg noodles can replace Italian pasta. If the nuts need to be toasted, spread them in a pan and bake at 350°F until they just begin to color and their husks split,