1Boil the potatoes in salted water for 30 minutes, Drain and by prensapurés.
2Add butter and milk and whisk until smooth.
3Add the grated cheese and egg yolk.
4Season with salt and pepper and stir.
5Then add the chopped sardines, parsley and pepper.
6Mix and add the beaten egg whites to stiff.
7Finally,, Pour batter into a greased pudding basin with butter and bake in a bain marie in the oven, pre-heated to 180 ° C for one hour.
8Remove from pan and place on a serving dish.
9Cover with bechamel sauce and garnish to taste.