2 1/2 pounds russet potatoes
6 large egg yolks, room temperature
6 tablespoons unsalted butter, cut into 8 pieces, room temperature
1/4 cup heavy cream, room temperature
1 teaspoon salt
1/4 teaspoon black pepper
1/8 teaspoon nutmeg
1/2 cup finely shredded Swiss cheese
Preheat oven to 400 degrees. Grease baking pans.
Wash and peel potatoes, cut into 1 1/2″ chunks, and place in a large saucepan. Cover potatoes with 2″ of cold water and salt water when it comes to a boil. Reduce heat to a low simmer for about 15 minutes.
Drain potatoes, return the potatoes to the pot, and mash until smooth.
While potatoes are warm, mix in egg yolks one at a time with a wooden spoon or spatula. Make sure each yolk is completely mixed before adding the next. Add butter, cream, salt, pepper and nutmeg. Stir until mixture is smooth.
Transfer potato mixture into a piping bag with star tip and pipe 12 round mounds onto each pan. Mounds should be about 2″x2″ and 2″ apart. Sprinkle with cheese.
Place baking pans into oven and bake for 15 minutes. Rotate pans and bake for an additional 10 minutes.