Ingredients: - 
20g butter plus a little for greasing the tray
1 onion, peeled and thinly sliced
1 clove garlic, crushed
1.1 kg potatoes
300 ml cream
Sea salt and freshly ground black pepper
A pinch of freshly ground nutmeg  
METHOD: - 
Preheat the oven to 204° C.
Lightly butter an oven dish, about 6 cm x 15 cm x 25cm,
In a wok or frying pan, melt the butter and gently fry the onions and garlic for 4 mins until softened,
Thinly slice the potatoes to 5mm (¼”), I prefer the skins to be left on, but that's your choice. A food processor is good for this job.
Mix the cream, salt, pepper and nutmeg in a bowl and whisk until combined well.
Arrange the potato slices and onions and a little cream in layers until everything is used.
Cover with tin foil and bake for 40 mins until the potatoes are soft.
If using grated cheese, then add at this stage.
Remove the foil and cook for a further 30 mins to brown the dish. 
A wonderful addition to the Xmas menu.