1 Peel the potatoes and, using a mandolin, cut into about 0.04 inch (1 millimeter) thick slices.
2 Spread the olive oil over the surface of the frying pan using a pastry brush.
3 Arrange the potatoes into a rosette, then add the thyme.
4 Put the pan over medium heat and cook, covered, for 10 min. Preheat the oven to 365°F (180°C)
5 Place cubes of butter on the potatoes and season.
6 Bake for 35 minutes.
Tips: you can add cheese such as grated Comté during the last 10 minutes of cooking.