1Put the butter, oil, garlic, salt and pepper in a small saucepan over low heat. Heat for 3-4 minutes until the butter has melted and the salt dissolved. Cover to keep warm.
2Cut a thin slice from the bottom of each potato to create a flat, stable base. Place one potato lengthwise between 2 chopsticks or flat-handled wooden spoons. Cut slits into the potato, 1/8-inch apart, stopping when the knife hits the chopsticks. Repeat with the remaining potatoes.
3Insert the wire rack into the middle shelf position. Preheat the oven. Select ROAST/CONVECTION/425°F/45 minutes and press start.
4Grease the roasting pan. Place the potatoes in the roasting pan, flat side down. Brush generously with the garlic butter mixture.
5Once preheated, put the potatoes in the oven and roast for 30 minutes.
6Remove the pan from the oven, brush the potatoes with the remaining garlic butter mixture and return to the oven.
7Roast for another 15 minutes until the potatoes are golden and tender.
8Transfer to a serving plate, sprinkle with chives and parsley and serve.