This creamy cheese sauce gets its signature nutty flavor from Gruyere, a Swiss cheese that melts beautifully. Use it to make our savory Chicken Crepes.
Melt butter in a medium saucepan over medium heat until foamy. Add flour and cook, stirring frequently, until mixture is pale golden and has a slightly nutty aroma, about 5 minutes. Stir in Dijon.
Whisking constantly, pour in 2 cups milk and whisk until smooth. Cook over medium-high, whisking often along the bottom of pan, until boiling, about 7 minutes.
Reduce heat to maintain a simmer. Add nutmeg and cook, stirring occasionally, until sauce thickens to the consistency of thin yogurt, about 10 minutes. Stir in Gruyere. Season with salt and pepper.
When cooling the bechamel, dot the top with butter to keep a skin from forming.