Duchess Potato Casserole

This Duchess Potato Casserole combines creamy Yukon gold potatoes, Gruyère cheese, and a hint of nutmeg—topped with golden, buttery rosettes for a beautiful and comforting holiday side dish.

Recipe Information

Total Time:

Yield:

12 servings (¾ cup each)

Ingredients

1 (5-pound) package Yukon gold potatoes, peeled and cut into 1-inch chunks

Coarse kosher salt for cooking potatoes

6 tablespoons salted butter, melted; divided

4 large egg yolks

1 (7-ounce) package Gruyère cheese block, shredded

½ cup heavy whipping cream

½ teaspoon coarse kosher salt

½ teaspoon ground white pepper

¼ teaspoon ground nutmeg

Finely chopped Italian parsley, for garnish

Directions

In a stockpot or very large saucepan, cover potatoes with cold salted water. Cover with lid and bring to a boil over high heat. Reduce heat to medium. Cook, covered, for 20 to 25 minutes or until potatoes are fork-tender.
Meanwhile, place oven rack in center of oven; preheat oven to 450°F. Grease a 2-quart oval baking dish with 2 tablespoons melted butter.
Drain potatoes using a colander. Let potatoes stand in colander for 10 minutes to ensure excess water is removed.
Using a potato ricer or food mill, rice cooked potatoes, about 1 cup at a time. Transfer riced potatoes to stockpot or saucepan.
Stir 2 tablespoons melted butter, egg yolks, shredded cheese, cream, ½ teaspoon salt, white pepper, and nutmeg into potato mixture.
In the prepared baking dish, evenly spread 5 cups of the potato mixture; smooth top with an offset spatula. Spoon remaining potato mixture into a pastry bag fitted with a large open star-shape piping tip. Starting at one corner of the baking dish, pipe large rosettes. Brush potato rosettes with remaining 2 tablespoons melted butter.
Bake potato casserole, uncovered, for 25 to 30 minutes or until peaks are puffed and the top is evenly browned, rotating baking dish on oven rack as needed.
Remove from oven; cool slightly. Garnish with chopped parsley, if desired.