This is a simple, but classic, Sicilian pasta that has Arabic overtones. The sauce is made with fennel, raisins, sardines and pine nuts. It is usually spooned over a broad or tubular pasta and then topped with a generous sprinkling of toasted breadcrumbs. While I have chosen a simple toss and top application, some cooks prefer to create multiple layers using these ingredients. The breadcrumbs in the dish are used in place of cheese and at one time they actually served that function for the poor. They also have a symbolic importance for those who observe St. Joseph's Day. As you know, Joseph was a carpenter and the breadcrumbs that crown this dish are used because they resemble the sawdust that would be found on the floor of a carpenter's workshop. Pasta con sarde is also known as St. Joseph's pasta, and in those communities where his feast day is still celebrated, you'll find this pasta on family tables, as well as on symbolic altars set up to feed the poor.