Step 1

Preheat oven to 200C/180C fan-forced. Heat cream, garlic and thyme in a small saucepan over medium heat for 6 minutes or until just simmering. Remove from heat. Season with salt and pepper. Set aside for flavours to infuse.

Step 2

Meanwhile, place 1 potato half, cut-side down, on a chopping board. Position a bamboo skewer on each side of potato. Using a small sharp knife, cut thin slices in top of potato at 3mm intervals, being careful not to cut the whole way through potato (skewers will help to prevent this). Repeat with remaining potato halves.

Step 3

Grease a 4cm-deep, 25cm x 35cm (base) roasting pan. Place potatoes, flat-side down, in prepared pan. Sprinkle with 1/2 cup cheddar and 1/2 cup parmesan. Strain cream mixture through a fine sieve into a jug. Discard solids. Pour cream mixture over potatoes. Cover pan with foil. Bake for 40 minutes or until potatoes are just tender.

Step 4

Remove foil. Sprinkle potatoes with remaining cheese. Bake, uncovered, for a further 40 minutes or until potatoes are golden and tender. Sprinkle with extra thyme sprigs. Season with salt and pepper. Serve.