Heat the oven to 200C/fan 180C/gas 6. Use a metal skewer and insert through the back of one of the flatter sides of a potato. It should go through most of the potato. Place on a chopping board, skewer-side down, and slice through the potato (be careful not to cut all the way through on both ends). You can also put each potato in-between two handles of wooden spoons, and cut through to the spoon, if this is easier for you. A sharp knife will help to make slices a few mm apart. Remove the skewer and repeat with the remaining potatoes.

Put the potatoes cut-side up in a shallow oven proof dish. Take one potato at a time and insert a slice of garlic and then a small sprig or a few leaves of rosemary, alternately into each cut.   Once all of the potatoes have garlic and rosemary in them, season them with salt and freshly ground black pepper and then drizzle them with olive oil.

Roast for 1 hour until the potatoes are tender throughout and the tops are golden and crisp. A delicious side to enjoy with chicken, pork and steak!