Takes a bit of preparation but great for a dinner party since you can prepare it in advance and then just put in the oven on the night.
Start with about 900g of King Edward or desiree potatoes. Peel and then slice thinly. Wash them in cold water and then pat dry with a clean tea towel.
Get a baking dish and arrange a layer of potatoes. Season with some crushed garlic and salt and pepper and repeat. When you have finished with the potatoes you need to mix together 200ml of double cream and 200ml milk and pour over the potatoes.
Grate over some fresh nutmeg and season. Then dot with some butter.
Bake at about 160 degrees for 1.5-2 hours until it is bubbly and crisp on the top but soft underneath.