Serves 4-6
Ingredients
Melt the butter in a large saucepan and stir in the flour. Cook for a couple of minutes making sure the mixture doesn't burn. Add the milk slowly, stirring, keeping it thick so that no lumps form. Cook gently for a couple more minutes. Leave to cool for a few minutes.
Meanwhile separate the eggs. Whisk the whites until peaks form [see tip]. When the sauce mixture is cooler, stir in the yolks one by one then the grated cheese. Put a dollop of the eqq white in the mixture and lightly stir it together. Continue adding the white, stirring (folding) until each dollop has combined with the sauce to produce a foamy liquid.
Grease a high-sided oven-proof dish which is about twice the volume of the mixture you have made. Pour the mixture into the dish and bake for about 35 minutes at 180C. Serve immediately.