Ingredients:
• 1 tablespoon butter
• 4 pounds russet potatoes, peeled, cut into 1-inch pieces
• 1/2 cup whole milk
• 1/2 cup cream
• 1/2 cup (1 stick) butter, melted
• 1 1/2 cups grated mozzarella
• 1 cup freshly grated Parmesan
• Salt and freshly ground black pepper
Directions:
• Preheat the oven to 400 degrees F.
• Coat a 13 by 9 by 2-inch baking dish with 1 tablespoon of butter and set aside.
• Cook the potatoes in a large pot of boiling salted water until they are very tender, about 15 minutes.
• Drain; return the potatoes to the same pot and mash well.
• Mix in the milk, cream and melted butter.
• Mix in the mozzarella and 3/4 cup of the Parmesan.
• Season, to taste, with salt and pepper.
• Transfer the potatoes to the prepared baking dish.
• Sprinkle the Parmesan cheese over the mashed potatoes.
• Recipe can be prepared up to this point 6 hours ahead of time; cover and chill.
• Bake, uncovered, until the topping is golden brown, about 20 minutes.
