Ingredients:

  • 1 lb (450g) spaghetti or linguine
  • 1 tbsp (15g) kosher salt
  • 4 tbsp (57g) unsalted butter
  • 2 tbsp (30ml) extra virgin olive oil
  • 4 cloves (20g) garlic, minced
  • 1 tsp (2g) red pepper flakes
  • 1 tbsp (6g) lemon zest
  • 3 tbsp (45ml) fresh lemon juice
  • ½ cup (50g) freshly grated Parmesan cheese
  • ¼ cup (15g) fresh parsley, chopped
  • Salt and black pepper to taste

Instructions:

  1. Bring a large pot of salted water to a boil. Add the pasta and cook until al dente (usually 1–2 minutes less than package directions). Before draining, reserve 1 cup (240ml) of the starchy pasta water.
  2. Heat the olive oil and 2 tbsp (28g) of the butter in a skillet over medium-low heat. Add the minced garlic and red pepper flakes, sautéing for 2 minutes until fragrant and translucent. Stir in the lemon zest and cook for another 30 seconds.
  3. Increase heat to medium. Pour in the fresh lemon juice and ½ cup (120ml) of the reserved pasta water. Simmer for 2 minutes. Add the remaining 2 tbsp (28g) of butter and whisk rapidly until the sauce is opaque and velvety.
  4. Transfer the cooked pasta directly into the skillet. Toss vigorously with tongs for 1–2 minutes over medium heat. Sprinkle in the Parmesan cheese and chopped parsley, adding more reserved pasta water if needed to achieve a glossy sheen.