Set the oven to 210 degrees C, air circulation, rack in the middle.

Wash and peel the potatoes, then slice them in 3 mm thickness using a mandolin and place them in a bowl filled with cold water for 2 hours so that the excess starch is removed.

Take out of the water and dry them with a towel. Keep them out for 10 minutes to ensure that they have dried from the water.

Place the chips in a large bowl. Pour half of the oil and add the thyme, salt and pepper. Toss well.

Use an oven-proof baking dish, line it with the rest of the oil and place the chips slightly overlapping each other and cook for 35-50 minute until the edges of the chips brown a bit.