1 tsp unsalted butter
1 large clove garlic
1 cup heavy whipping cream
1/3 cup whole milk
1 tsp salt
1/8 tsp ground black pepper
2 lbs. potatoes, sliced 1/8" thick
1 cup gruyere, grated
1/4 cup Parmesan cheese, grated
Heat oven to 350 degrees.
Lightly butter a 2-quart shallow baking dish
Lightly crush garlic with side of knife. Heat cream, milk, garlic, salt and pepper in a small saucepan over medium heat until small bubbles appear around the edge. Remove from heat and let stand 10 min.
Arrange half the potatoes in overlapping slices along the bottom the prepared dish. Pour half the cream mixture over the potatoes, then sprinkle with half the cheese. Repeat with remaining potatoes and cheese.
Bake 60-70 minutes until top is a deep brown and potatoes are tender when pierced with a knife.