Preheat the oven to 180C/350F/Gas 4.
Bring the cream to the boil in a frying pan and then add the potatoes and garlic. Using a wooden spoon, separate the potato slices into one layer across the bottom of the pan, season well with salt and freshly ground black pepper and simmer for 4-5 minutes.
Transfer the potatoes to a gratin dish, scatter over the cheese and bake for 8-10 minutes, or until golden-brown and bubbling. Serve with the chopped chives scattered over the top.