Hasselback potatoes

The ingredients :

•     18 medium potatoes (oval shaped) or 36 new potatoes
•     Maldon salt
•     5 tablespoons olive oil
•    45 grams butter

Steps for preparation :

1.     If you're using the larger potatoes, preheat the oven to 210°C/gas mark 7/425ºF;  for roasting new potatoes, preheat to 200°C/gas mark 6/400ºF.
2.  Put each potato, in turn, in the bowl of a wooden spoon, its similar to if  you would carry an egg in an egg-and-spoon race, and cut across at about 3mm / one-eighth of an inch intervals.
3.     After  you've cut them , You should put the baking tin on the hob with the butter and oil and heat up till sizzling. After that, Turn the potatoes well, putting them in upside down (ie, cut side down) first, then the right side up, and spoon the fat over them.
4.     Before  putting the potatoes  in the oven, Sprinkle each potato well with salt : cook the large potatoes for about 80 minutes, testing to see if  the flesh is soft (you may need additional 10 minutes for this); 40 mines should be fine for the new potatoes.
5.     BEFORE SERVING.  Transfer to a warmed plate.