Special Potatoes

1.5kg Potatoes(Maris Piper or Desiree), peeled and thinly sliced
Salt and pepper
1 Large onion, thinly sliced
25g Plain flour
25g Butter, cut into small cubes
150g Good quality cheddar cheese, grated
200ml Full fat milk
400ml Single cream
Preheat oven to 180C. Place one layer of the potatoes in an ovenproof dish, overlapping them slightly (this should use up about a quarter of the potatoes). Season and scatter over a quarter of the onions.
Sprinkle a quarter of the flour on top, dot with a quarter of the butter and sprinkle with a quarter of the cheese. Repeat until there are 4 layers. Heat the milk and cream in a small pan but do not boil. Pour over the potatoes. Cover with foil and bake for 1 hour. Remove foil and return to the oven.
Bake for another 15-20 minutes until potatoes are tender and top is brown.
This is potato dauphanoise on steroids!