In a saucepan heat heavy cream, milk, thyme, garlic, nutmeg, salt, and pepper over medium high. Do not boil, just bring to a light simmer and cook for 10 minutes. Remove from heat and strain. Stir frequently to avoid scalding the milk.
Using a mandolin or sharp knife slice potatoes to about 1/8 inch thick.
Grease a 13x9 inch baking dish. Layer about 1/3 of the potatoes into the dish. Pour 1/3 of the cream mixture over potatoes. Continue with 2 more layers.
Place cubes of butter over the potatoes. Cover with foil and bake for 45-55 minutes until potatoes are cooked.
Remove foil and heat under broiler for about 5 minutes until golden brown.