Melt the Butter: In a medium saucepan, melt 3 tablespoons of butter over medium heat. Avoid browning.Make the Roux: Add 3 tablespoons of all-purpose flour and whisk continuously for 2–3 minutes until slightly nutty.Gradually Add Milk: Slowly pour in 2 cups of milk while whisking constantly to avoid lumps.Add Stock and Seasonings: Pour in ½ cup of stock, then add salt, white pepper, and a pinch of nutmeg. Simmer on low heat for 5–7 minutes until thickened.Taste and Adjust: Adjust salt and pepper as needed. Add extra milk or stock if sauce is too thick.Optional Variations: Add grated cheese, a few drops of soy sauce, or sautéed mushrooms/onions for extra flavor.Serve or Store: Use immediately in dishes like cream stew, doria, croquettes, pasta, or vegetable gratin. Store leftovers in an airtight container in the fridge for up to 3 days.