Gruyere Bechamel

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.