Ingredients:

  • 1 lb spaghetti dry
  • 2 tbsp kosher salt
  • 1/4 cup extra virgin olive oil
  • 4 tbsp unsalted butter cold and cubed
  • 6 cloves garlic thinly sliced
  • 1/2 tsp red pepper flakes
  • 2 large lemons zested and juiced
  • 1 cup freshly grated parmesan cheese
  • 1/2 cup fresh flat-leaf parsley finely chopped
  • 1/2 tsp freshly cracked black pepper
  • 1 cup starchy pasta cooking water (reserved from cooking pasta)

Instructions:

  1. Bring a large pot of water to a boil and add 2 tablespoons of kosher salt. Cook the spaghetti for 2 minutes less than the package instructions until very al dente.
  2. While the pasta cooks, heat the extra virgin olive oil in a 12-inch skillet over medium heat. Add the sliced garlic and cook until fragrant and pale golden brown.
  3. Stir in the red pepper flakes and lemon zest. Add the cold cubed butter and one ladle (about 1/2 cup) of the starchy pasta cooking water. Whisk or swirl the pan until the butter melts and emulsifies into a glossy sauce.
  4. Use tongs to transfer the undercooked spaghetti directly from the water into the skillet. Increase heat to medium-high.
  5. Add the lemon juice and grated Parmesan cheese. Toss vigorously for 1-2 minutes, adding more pasta water if needed, until the sauce clings to the pasta and the noodles are perfectly cooked.
  6. Remove from heat. Fold in the fresh parsley and cracked black pepper. Serve immediately.