1. Bring a large pot of water and 2 teaspoons salt to a boil over medium-high heat. When the pot of water boils, add the bucatini and cook until al dente, then drain. Reserve a cup of the pasta water to thin the sauce.

2. Prep the fennel, sardines, onion and tomatoes. Lightly toast the pine nuts in a small skillet, then remove them to a plate. Soak the raisins in 1/4 cup of boiling water for 10 minutes.

2. Meanwhile, heat a large skillet over medium-high heat. When it's hot, add the olive oil and the fennel. Season the fennel lightly with salt and pepper, reduce the heat to medium and cook, stirring occasionally, until the fennel is soft and brown in spots, 10 minutes.

3. Add the onions, tomatoes, raisins and pine nuts to the pan with the fennel. Bring the sauce to a boil, then reduce the heat to a simmer. Add the chopped sardines and cook, stirring occasionally, until the sardines begin to break down, 10-15 minutes.

4. Coat the sardine fillets with semolina flour and shake off the excess. In the small skillet you used to toast the pine nuts, heat enough olive oil to cover the bottom over medium-high heat. When it's hot and shimmering, add the sardines fillets. Cook them until golden brown, 2-4 minutes per side. Drain them on a paper towel-lined plate or wire rack.

5. The pasta sauce should be thick but pourable. (If it's too thick, add a ladleful of the pasta water.) Add the drained pasta to the sauce and toss to combine. Sprinkle over the fennel fronds and fried sardines.