Ingredients:
- 4 Tbsp (56 g) Unsalted Butter
- 4 Tbsp (30 g) All-Purpose Flour
- 2 ½ cups (600 ml) Whole Milk
- ½ tsp Fine Sea Salt
- ¼ tsp White Pepper
- Pinch Freshly Grated Nutmeg (Optional)
Instructions:
- Warm the Milk: Gently warm the 600 ml of whole milk in a separate small saucepan or microwave until steaming but not boiling. Keeping it warm prevents the roux from shocking and lumping later.
- Melt the Butter: In the medium saucepan, melt the butter over medium heat. Do not allow it to brown (we are aiming for a white roux).
- Add Flour (The Roux): Once the butter is melted and foaming slightly, add the flour all at once.
- Cook the Roux: Whisk vigorously for 1–2 minutes. The paste should bubble and smooth out, losing its raw, dusty flavour. This is the Roux Blanc (white roux).
- Incorporate the Milk (First Pour): Remove the saucepan from the heat briefly. Pour in only about one-third of the warm milk.
- Vigorous Whisking: Immediately and aggressively whisk the mixture until the milk is fully incorporated and the sauce is completely smooth and very thick—like a slurry. This initial incorporation prevents lumps.
- Incorporate Remaining Milk: Return the pan to low heat. Gradually pour in the remaining milk, whisking continuously as you pour.
- Simmer and Thicken: Bring the mixture to a gentle simmer, stirring constantly. Once boiling, the sauce will visibly thicken. Reduce the heat and simmer for 5–7 minutes to cook out the flour taste, ensuring the sauce coats the back of a spoon (nappé consistency).
- Season: Remove the sauce from the heat. Stir in the salt, white pepper, and the pinch of nutmeg. Taste and adjust seasoning as necessary.
- Strain (Optional but Recommended): For an exceptionally smooth finish, pour the sauce through a fine-mesh sieve into a bowl.
- Prevent Skin: If not using immediately, cover the sauce surface directly with cling film (plastic wrap) to prevent a skin from forming.