Peel the potatoes and place in a bowl of cold water, whilst you peel the others. Once they are all peeled, using a mandoline if you have one, or a sharp knife, very carefully, thinly slice all of the potatoes.
Grease a 28 centimeters roasting tin that's suitable for the oven, and start layering in the potatoes. Once one layer is done, season and add in a sprinkle of the garlic, cheese and thyme leaves and break in a knob of butter randomly dotting over the potato layer. Repeat with the remaining potato, finishing with just a layer of potatoes.
Preheat the oven to 180C. Top the potato dish with the cream so the potatoes are covered. Place in the oven for about 50 minutes, until golden and bubbling and
Once out of the oven, leave to cool and cut into chips.
Get the frying oil up to temperature and fry the potatoes until the are crisp, just a couple of minutes.