ricetta Cotechino crust with Castelmagno Marenchino sauce

Ingredients (for 4 people if served as a starte)
A cotechino (a stuffed pig's trotter), 200 gr. of ready-made pastry crust, a large boiled potato, 120 gr. Castelmagno Marenchino, 3-4 tablespoons of milk, 2 tablespoons of cream, half a tablespoon of Perla butter, one egg, pepper.

Cook the cotechino for about an hour and a quarter and then pull it out of the water, removing the skin and allow it to cool slightly. Roll out the pastry, cover its surface with a mixture of a beaten egg yolk and a tablespoon of milk. Lay the potato, thinly sliced, leaving the edges free, put the cotechino in the middle, then wrap it completely into the pastry and seal its edges.

Put it on a baking tray covered in greaseproof paper, brush its surface again with the rest of the egg and bake at 180-190°C until the pastry is well cooked and golden brown. In a small saucepan, heat the butter with the milk and cream, add the crumbled Castelmagno and keep on low heat until it is completely melted.
Cut the cotechino and serve it by pouring a little sauce on each slice.