Based on bbcgoodfood recipe
a couple of
Heat the fan oven to 190c.
Peel the potatoes and thinly slice with a mandoline.
Pour the cream and milk into a large saucepan and heat.
Add the sliced potatoes to the pan and bring to a simmer, stirring to stop the tatties sticking to the bottom.
Take the tatties out with a slotted spoon and put them into an ovenproof dish to about 5cm deep.
Pour the remaining sauce (removing garlic) so a little seeps to the surface.
Grate cheddar over the top.
Pop it in the oven for 30 minutes until golden brown on top.