Ingredients:

  • 4 Tablespoons Unsalted Butter (56 grams)
  • 2 cloves Garlic, minced (optional)
  • 4 Tablespoons All-Purpose Flour (30 grams)
  • 2 cups Whole Milk, warmed (475 ml)
  • 1/4 teaspoon Ground White Pepper
  • Pinch Freshly Grated Nutmeg
  • Kosher Salt, To taste
  • 1 cup (packed) Parmigiano-Reggiano, finely grated (110 grams)
  • 1/2 cup Reserved Pasta Water (120 ml)

Instructions:

  1. Melt the Butter: In a medium saucepan over medium-low heat, melt the unsalted butter completely.
  2. Sauté Aromatics (Optional): If using garlic, add the minced garlic now and sauté for about 30 seconds until fragrant, ensuring it does not brown.
  3. Make the Roux: Whisk in the flour thoroughly until a smooth paste forms (the Roux). Cook, stirring constantly, for 1 to 2 minutes over low heat until the raw flour smell is gone and the Roux smells nutty.
  4. Temper the Milk: Remove the pan from the heat briefly. Slowly pour in about 1/4 cup of the warm whole milk, whisking vigorously until fully incorporated and smooth to prevent lumps.
  5. Add Remaining Milk: Gradually whisk in the remaining warm milk, increasing the heat back to medium-low.
  6. Thicken: Bring the mixture to a gentle simmer (small bubbles should just start breaking the surface). Continue simmering, stirring frequently, for 5 to 7 minutes, or until the sauce coats the back of a spoon thickly.
  7. Season: Season the sauce with salt, white pepper, and a generous pinch of nutmeg. Taste and adjust seasoning.
  8. Remove from Heat: Once the sauce has thickened sufficiently, turn the heat off completely. This step is non-negotiable—adding cheese to boiling sauce guarantees clumping.
  9. Incorporate Cheese (Half): Immediately add half of the finely grated Parmigiano-Reggiano. Stir rapidly with a spatula or wooden spoon until the cheese is melted and fully incorporated, creating an emulsion.
  10. Finish Cheese: Add the remaining cheese and stir until the sauce is glossy, silky, and homogenous.
  11. Adjust Consistency: If the sauce is too thick, add a tablespoon of the reserved pasta cooking water at a time, stirring until the desired silky consistency is achieved. Serve immediately over fresh pasta.