1Using a food processor, slice the potatoes into 3mm thick slices and place in a bowl.
2Add the cream, salt, pepper, thyme and garlic to the potatoes and mix to coat.
3Layer the potatoes in a 19cm x 25cm x 6cm deep baking dish. Pour over the cream that is left in the bowl and sprinkle with the cheese. Cover with a sheet of parchment paper then foil. The parchment paper stops the cheese sticking to the foil.
4Insert the wire rack in the middle position. Set the oven to Bake, Convection, 175°C, for 1 hour and press Start to preheat.
5Once preheated, place the dish in the oven and cook for 1 hour. After 45 minutes cooking, remove the foil and parchment paper, rotate the dish and continue cooking.
6The gratin should be golden brown. Test the potatoes with a skewer to check if they are tender. If not, cook it a little longer.
7Sprinkle with cracked pepper and chives and serve.