Spaghetti col Pesto alla Trapanese

America has long since fallen in love with the basil pesto of Genoa, but wait until people discover this spicy pesto sauce from Trapani. Dazzling to taste, incredibly simple to prepare, it is a sensational Sicilian alternative to the winning northern combination.

Antonietta de Blasi Rocca, the grandmother who gave me this recipe, insisted that it must be made in a mortar to get the right texture. That may make a difference, but I’ve made it