Directions

1. Bring a very large pot of heavily salted water to a boil.
2. Open the sardine tin and drain a tablespoon or so of the oil into a wide skillet (the amount of oil in the tin will vary by brand, so add additional extra virgin olive oil if necessary to make up a tablespoon). Warm the oil over medium-low heat and add the garlic, cooking until fragrant.
3. Trim the fennel and slice the bulb very thinly (a mandoline works great here). Add to the skillet with a sprinkle of salt, raise the heat to medium, and cook until the fennel is soft and beginning to caramelize. Add the chile flakes and let them sizzle for a minute, just until fragrant, then add the tomatoes with their juice. Cook until the liquid is reduced, then add the vermouth and let that reduce slightly.
4. Add the sardines to the skillet with the tomato and fennel mixture, breaking up slightly but leaving some chunks. Zest the lemon and combine a tablespoon or so of zest with the toasted breadcrumbs, then set aside. Juice the lemon and add the juice to the pan. Taste and adjust salt if necessary.
5. Add the linguine to the boiling salted water, cooking it until it is just short of al dente. Using tongs, transfer the linguine to the sauce to finish cooking, adding a little bit of the starchy pasta water and tossing gently to combine. (You'll want to leave this a little wet, as the breadcrumbs will soak up the sauce and dry the pasta out a bit once you've added them.)
6. Transfer the pasta and sauce to a large warmed serving bowl (or individual pasta bowls), add a drizzle of olive oil, sprinkle on the toasted breadcrumb-lemon zest mixture, and garnish with picked small fennel fronds and the remaining lemon zest.