Mix the Debic Cream Plus Mascarpone with the finely chopped garlic, parmesan cheese, pepper and salt.
Peel the potato and cut them into very thin slices (2mm) on the mandolin and mix them immediately under the cream mixture.
Line a baking tin with parchment paper, so that baking paper comes out over the edge on all sides.
Arrange the drained potato slices layer by layer in the baking tin. Press well from time to time.
Seal the gratin with the excess parchment paper. Bake in the oven at 170 °C for 1 hour.
Check whether the potato gratin is completely cooked by inserting a fine knife into the gratin.
Let the gratin cool and place under a weight in the refrigerator for 1 night.
Cut the cold gratin into bars.
Bake the bars until golden brown in a rich amount of Debic Roast & Fry. Keep them warm.