Gratin dauphinois

Preheat the oven to 180°C

Using a mandoline, finely slice the peeled potatoes into 2mm thick pieces. Meanwhile, add the milk, cream, salt, garlic and Parmesan to a large, wide pan and heat until the mixture begins to simmer

Add the potato slices to the pan with the simmering sauce, stir to combine and leave to cook for 5 minutes until the potatoes release their starch and the mixture thickens. Check the seasoning, and pour into an oven proof gratin dish

Cover the dish with baking parchment and foil, then place the dish into a large, deep baking tray. Fill the baking tray with water to surround the gratin dish, and bake the dauphinois in the oven for 1 hour. If you don't have a suitable baking tray, place the gratin dish directly in the oven and cook at a reduced heat of 160°C for 90 minutes

Remove the baking paper and foil from the top of the dish for the final 20 minutes of cooking and serve immediately. If you are preparing the dauphinois in advance, keep the dish covered and reheat under the grill when required