In a medium saucepan over medium-low heat, melt 3 tablespoons of unsalted butter. Stir in the all-purpose flour and whisk continuously for about 2 minutes until the mixture becomes bubbly and turns a light, blond color. Avoid browning the mixture.

Slowly pour in the chicken stock while whisking continuously to avoid lumps. Add salt and white pepper. Increase the heat slightly and bring the mixture to a low simmer, whisking constantly for about 2-5 minutes until the sauce is smooth and slightly thickened.

Optionally, dot the sauce with 1 teaspoon of unsalted butter over the top to prevent a skin from forming. Remove from heat and serve immediately, or use as a base for other dishes.

Taste and adjust seasonings if needed before serving.