Melt 1 oz.butter in a saucepan, add the flour and cook over a low heat for 2 minutes.
Add the milk gradually, stirring all the time until the sauce thickens.
Remove from the heat and stir in the beaten egg yolks.
Thinly slice the onion, tomatoes and garlic and fry in 1 oz.butter.
Add this to the sauce, with the chopped pork luncheon meat and the mashed Danish blue cheese.
Whisk the egg whites till stiff and fold into the mixture.
Put the mixture into a buttered ovenproof dish.
Bake in a very hot oven (475°F - Gas Mark 8) for 10 minutes, then turn down to moderate (375°F - Gas Mark 4) for 20 minutes.