Preheat the oven to 400 degrees F. Butter a shallow baking dish and set aside.Dice the potatoes. Place them in the buttered dish. Combine the milk and cream in a bowl. Add the flour, garlic, salt and pepper and whisk. Pour over potatoes.Cover with foil and bake for 30 minutes. Remove the foil and and bake for another 20-30 minutes. Just before serving, sprinkle with cheese and bake for another 3-5 minutes or until cheese is melted and bubbly.Sprinkle on the chives and serve immediately.