Ingredients:

  • 3 Tablespoons Unsalted Butter
  • 1 small Shallot, finely minced (Optional)
  • 3 Tablespoons All-Purpose Flour
  • 1/4 cup Dry White Wine (e.g., Sauvignon Blanc)
  • 2 cups Whole Milk
  • 1 cup, packed Gruyère Cheese, freshly grated
  • 1/4 cup Parmesan Cheese, finely grated
  • 1 teaspoon Dijon Mustard
  • 1/4 teaspoon Freshly Grated Nutmeg
  • 1/2 teaspoon Kosher Salt (or to taste)
  • 1/4 teaspoon Freshly Ground Black Pepper (or to taste)

Instructions:

  1. Melt the Butter: Place the heavy-bottomed saucepan over medium heat. Add the unsalted butter and allow it to melt completely.
  2. Sauté Aromatics (Optional): If using, add the minced shallot and sauté gently for 3-4 minutes until softened and translucent, but not browned.
  3. Create the Roux: Sprinkle the all-purpose flour over the melted butter/shallots. Whisk constantly for 1–2 minutes until the mixture forms a smooth paste (the roux). Cook until the raw flour smell is gone (it should smell slightly nutty).
  4. Deglaze (If Using Wine): Pour in the white wine and whisk vigorously for 30 seconds until the liquid is fully absorbed into the roux.
  5. Add the Milk: Pour in about 1/2 cup (120ml) of the milk while whisking aggressively to immediately prevent lumps. Once smooth, slowly incorporate the remaining milk, pouring in a steady stream while continuously whisking.
  6. Thicken: Bring the mixture to a gentle simmer, stirring frequently. Reduce the heat to low and allow the sauce to simmer for 5–8 minutes, or until it coats the back of a spoon (nappe consistency).
  7. Remove from Heat: Once thickened, remove the saucepan from the heat source. This is vital to prevent the cheese from splitting or becoming grainy.
  8. Add Flavouring: Stir in the Dijon mustard and freshly grated nutmeg.
  9. Melt the Cheese: Gradually add the grated Gruyère and Parmesan cheeses, stirring constantly until fully melted and smooth. Do not boil the sauce once the cheese is added.
  10. Seasoning Check: Taste the sauce and adjust the kosher salt and pepper as needed. If the sauce is too thick, whisk in a tablespoon of milk or cream until the desired consistency is achieved. Serve immediately.