A white sauce enriched with cheese and egg yolks makes a perfect topping for the scallops shown here. To finish, simply flash under the grill until golden brown.
Melt the butter in a heavy-based pan over low-medium heat. Sprinkle the flour over the butter and cook for 1–2 minutes without allowing it to colour, stirring continuously with a wooden spoon.
Remove the pan from the heat and slowly add the milk, whisking to avoid lumps. Return to medium heat and bring to the boil, stirring constantly. Cook for 3–4 minutes, or