This sauce is a classic béchamel-based cheese sauce made by combining butter, flour, and milk with grated cheese. It’s smooth, flavorful, and can be customized with different cheeses and seasonings to suit your dish.
In a saucepan over medium heat, melt the butter. Add the flour and whisk continuously for 1-2 minutes to form a smooth paste (roux).
Gradually pour in the milk, a little at a time, whisking constantly to prevent lumps. Continue whisking until the mixture is smooth and begins to thicken.
Reduce the heat to low and stir in the grated cheese until fully melted and combined.
Stir in the Dijon mustard (if using) and season with salt, white pepper, and a pinch of nutmeg. Taste and adjust seasoning as needed.
Use the cheese sauce immediately for your dish or keep warm on low heat, stirring occasionally.
Find it online: https://britishbakingrecipes.co.uk/mary-berry-cheese-sauce/