Place the potatoes on a wooden spoon or between two Chinese chopsticks and make a 3 mm cut. This way, the bottom is not cut through and the shape of the potato is retained.
Melt the butter and add the oil, garlic and herbs.
Place the potatoes in the oiled dish and brush with the butter / oil mixture and cook in the oven for 45 minutes to 1 hour (depending on the size and type of potatoes).
During the cooking process, the potatoes open like a fan.