Bring a large pot of water to a rolling boil. Add 1 tablespoon coarse salt. Add 12 oz linguine and cook until just shy of al dente (about 9 minutes or according to package minus 1 minute). Reserve 1 cup of the starchy cooking water and drain the pasta, keeping it warm.

Sourdough pangrattato (breadcrumb topping)

Toast crumbs

Heat a large skillet over medium heat. Add 3 tablespoons olive oil. When warm, add the 3 cups cubed sourdough bread and 1 minced garlic clove. Toast, stirring frequently, until golden and crisp, about 6–8 minutes. If using the optional anchovy, stir it in during the last 2 minutes so it melts into the crumbs.

Finish crumbs

Remove skillet from heat. Stir in 2 tablespoons finely grated Parmigiano-Reggiano (or Pecorino), 1 teaspoon sea salt and 1 teaspoon lemon zest. Transfer pangrattato to a bowl and set aside. Return skillet to low heat to prepare the sauce.

Anchovy butter sauce

Melt butter and infuse

In the same skillet over low–medium heat, add 2 tablespoons extra-virgin olive oil and 6 tablespoons unsalted butter. When butter begins to foam, add the 6 finely chopped anchovy fillets and stir until they dissolve into the butter, about 1–2 minutes.

Add garlic & chilli

Add the 4 thinly sliced garlic cloves and the sliced fresh red chilli (or 1 tsp crushed flakes). Sauté gently until garlic is fragrant and just turning golden (about 1–2 minutes). Do not burn the garlic.

Emulsify sauce

Add 1 teaspoon fresh lemon juice and up to 1/2 cup reserved pasta water to the skillet and whisk to emulsify the butter into a silky sauce. Season with 1 teaspoon freshly ground black pepper. Taste and adjust: add a splash more pasta water if the sauce seems too thick or a pinch of salt only if needed (anchovies and cheese already salty).

Combine pasta and sauce

Add the drained linguine directly to the skillet. Toss and cook together over low heat for 1–2 minutes so the pasta absorbs the sauce, adding small amounts of the reserved pasta water as needed to achieve a glossy coating (use up to the reserved 1 cup total). Stir in 1 tablespoon chopped fresh parsley.

Finishing & plating

Portion the linguine into warmed shallow bowls. Spoon generous amounts of the sourdough pangrattato over each portion so it stays crisp on top. Drizzle each serving with 1 teaspoon extra-virgin olive oil, sprinkle remaining chopped parsley, and finish with additional black pepper to taste. Serve immediately.