Step 1

Preheat the oven to 220C/gas mark

Step 2

Peel the potatoes and rinse under cold water, then dry and slice very thinly by hand or with the slicer attachment on a processor. Put the stock into a large jug and mix with the cream. Arrange a layer of potato over the base of the tin, season with salt and freshly ground black pepper, then pour over a little of the stock mixture. Continue in the same way until the potato and liquid are used up. Dot the butter over the top and cover tightly with foil. Bake for 30 minutes or until soft around the edges but still firm in the middle. Remove the foil and cook for a further 25–-30 minutes or until golden and tender. Leave to cool, then chill – overnight is best. Choose a lipped board or tray that's bigger than the roasting tin (so it will catch any juices) and place on a worktop. Carefully tip the roasting tin upside down on to it and remove the paper. Cut the potatoes into even-sized servings, arrange on a greased or paper-lined baking sheet, and sprinkle the cheese on top. Reheat in an oven preheated to 200C/gas mark 6 for 25-30 minutes or until golden and piping hot.