Ingredients:
- 4 oz (115g) unsalted butter, cold, cut into small cubes
- 1 cup (120g) freshly grated Parmigiano-Reggiano cheese, finely grated
- 1/2 cup (120ml) reserved pasta water (from cooking pasta, obviously!)
- 1/4 teaspoon freshly grated nutmeg (optional, but highly recommended)
- Salt and freshly ground black pepper to taste
Instructions:
- Cook your pasta of choice according to package directions. Reserve at least 1/2 cup of pasta water before draining.
- In a large skillet over medium-low heat, melt the butter. Do not brown it!
- Reduce heat to low. Gradually add the grated Parmesan cheese to the melted butter, whisking (or stirring vigorously) constantly to prevent clumping.
- Slowly drizzle in the reserved pasta water, whisking continuously, until the sauce becomes smooth, creamy, and emulsified. It should coat the back of a spoon.
- Season with freshly grated nutmeg (if using), salt, and freshly ground black pepper to taste. Be careful with the salt, as the cheese is already salty.
- Immediately add the cooked pasta to the skillet and toss to coat thoroughly.
- Serve immediately. Garnish with extra grated Parmesan cheese and freshly cracked black pepper, if desired.