Heat the butter. Add the flour and sauté with the whisk while stirring continuously. Add the milk and bring to the boil as you continue to stir. Reduce the heat and let simmer for a further approx. 5 minutes. Season.
Take the pan off the hob and let it cool down somewhat. Separate the eggs. Mix the egg yolks with the fork and fold into the mixture together with the alp cheese. Whisk the egg whites until stiff and fold into the mixture.
Grease the bottom of the baking dish then pour in the mixture.
Bake on the lowest rack of the oven at 180° for approx. 45 minutes. Do not open the oven during the baking time.
Serve the soufflé with a salad. It is also great as a starter or to accompany meat and vegetables in a festive menu.