Start by preparing the sauce. Boil the peeled potatoes, season with a bit of salt and olive oil, add some wild fennel and blend everything with a food processor. At this point fillet the sardines, bread them with breadcrumbs, a little grated cheese and some spices you like. Sear the sardines in a pan with a drizzle of olive oil until golden brown. As the Bucatini are ready mix them in the pot along with the potato sauce and serve. Garnish with the sardines, the PomUp and a sprinkling of breadcrumbs (previously blanched with a knob of butter).