Put the raisins to soak in half a glass of warm water for 10 minutes. In the meanwhile clean the onion, slice it thinly and sauté it in a heavy-bottomed frying pan (large enough to contain the pasta later on) with 2 tablespoons of olive oil. When it’s golden, add the sardine fillets, which you have previously washed, patted dry with kitchen paper and cut into pieces. Add the Pesto al Finocchietto, the raisins (well squeezed) and ladle of warm water, and stir thoroughly. Put the lid on the pan and cook for roughly 3-4 minutes. Crumble the slices of bread and toast the crumbs in a heavy-bottomed frying pan with a tablespoon of olive oil, until they become crispy. Cook the linguine in plenty of boiling, salted water, strain them when they’re “al dente” and tip them into the frying pan with the sauce. Add the saffron, dissolved in a little warm water, and toss the pasta in the pan over a high heat, mixing it well with the sauce. Before serving, sprinkle with a handful of crispy breadcrumbs and some finely chopped parsley.