The following is my adaptation of the finest side-dish created by the mind of a mortal. The chef was Gerard Crozier. (I've cut the recipe in half, but did not alter any ingredient.) Below is the video from the Great Chefs PBS series.
Chop the garlic. Peel the potatoes. Cut the potatoes into thin slices. Smear butter on the bottom and sides of shallow round pan. Throw in some garlic. Layer the slices of one potato on the bottom of the pan. Add salt, pepper, garlic and butter to taste. Layer the slices of the other potato as above. Add salt, pepper, garlic and butter to taste. Pour in the heavy cream, filling about half-way up the sides. Add milk to barely cover. Stir potatoes thoroughly. Over the top, sprinkle a bit more salt and pepper.
Roast for 40-45 minutes, until the potatoes feel tender when poked with a knife.