Step 1

Preheat the oven to 375˚ F. Coat the bottom and sides of an 8-inch square baking dish with 1 tablespoon butter; set aside.

Step 2

Fill a large pot three-quarters of the way with water, then add the potatoes, garlic and a hefty pinch of salt and pepper. Bring to a boil and cook until a fork is easily inserted into the potatoes, but they still hold their shape, about 20 minutes. Drain in a colander, then place the colander over the empty pot, allowing the remaining heat to evaporate some of the moisture from the potatoes and garlic, just a few minutes. Return the mixture to the pot and mash well.

Step 3

Add the remaining 2 tablespoons butter and the heavy cream. Mash until smooth but if you like it chunky, leave it chunky. Then stir in 1 cup pepper Jack and 1/4 cup Parmesan. Spread in the prepared baking dish. Stir together the remaining 1/4 cup Parmesan, 2 tablespoons pepper Jack and the panko. Sprinkle the mixture evenly over the top of the potatoes. Bake until the top is golden brown, about 20 minutes. Serve warm.