Sift the chestnut flour; add the sugar and a pinch of salt. Add 50 cl cold water in a thin stream, beating constantly with a whisk so as not to form lumps. Add 3 tbsp oil, orange peel, raisins, pine nuts and walnuts. Add warm milk little by little until you get a stiff consistency. Pour the batter into a greased pan large enough for the crust to be 1/2-in. thick. Dribble on some oil. Pre-heat the oven to 200 degrees and bake for an hour. Serve warm or cold. It can also be served with whipped cream.