Ingredients
2 tablespoons extra-virgin olive oil
1 large yellow onion, very thinly sliced
1/2 teaspoon crushed red pepper flakes
kosher salt
1 serrano or other fresh small hot red or green chile, seeded and finely diced
4 ounces (1/2 cup) unsalted butter, cut into about 5 pieces
3 tablespoons fresh lemon juice
1 pound dried linguine
1/3 cup roughly chopped fresh flat leaf parsley
1 large clove garlic, finely chopped
1 teaspoon finely chopped lemon zest
1/2 cup grated pecorino romano cheese, more for sprinkling
Preparation
Bring a large pot of well salted water to a boil.
Meanwhile heat the oil in a 10 inch skillet over medium heat. Add the onion and red pepper flakes, season with a pinch of kosher salt and cook, stirring frequently, until tender and nicely browned, about 15 minutes (reduce the heat to medium low if the onion is browning to fast). Add the chile and continue to cook for 1 minute. Turn off the heat, add the butter, and swirl the pan to melt. Add the lemon juice and another pinch of kosher salt. Keep warm.
Cook the linguine in the boiling water until al dente, about 10 minutes.
Meanwhile make the gremolata:
Combine the parsley, garlic and lemon zest on a cutting board and chop them together with a chef’s knife until the parsley is finely chopped and mixed well with the lemon and garlic.
Drain the pasta and return it to its cooking pot. Over medium heat add the onion mixture to the pasta and toss to combine. Add the 1/2 cup pecorino, quickly toss again, and add salt too taste. Transfer the pasta to a platter or shallow bowls. Sprinkle liberally with the gremolata and more pecorino and serve.
