Recipe Light gratin of potatoes and Jerusalem artichokes

1. Peel and thinly slice the potatoes and Jerusalem artichokes. Blanch in unsalted water for at least 3 minutes. Drain. Set aside.
2. In a bowl, add the flour and gradually dilute with the milk, mixing well. Season with salt, pepper and nutmeg.
3. Arrange the slices in the terrines, making sure they are 2cm from the edge. Cover with the milk/flour mixture to within 2cm.
4. Close the terrines with the slices and heat for 2 hours at 100°C.

Recipe suggested by Appetia for Le Parfait.