• 5 tablespoons unsalted butter
• ¼ cup all-purpose flour
• 1 quart milk
• 2 teaspoons salt
• ¼ teaspoon freshly grated nutmeg

Melt the butter in a large saucepan over medium heat. Once melted, stir in the flour until smooth. Continue stirring as the flour cooks to a light, golden color, about 7 minutes.

Increase heat to medium-high and slowly whisk in milk until thickened by the roux (cooked flour mixture). Bring to a gentle simmer, then reduce heat to medium-low and continue simmering until smooth and thickens, about 10 to 20 minutes. Once the sauce no longer tastes gritty, season with salt and nutmeg.