1 piping bag with ½-inch star tip - alternatively, use a large plastic bag with a "W" cut into one corner
Ingredients
1½poundsyukon potatoes
4egg yolks
4tablespoonsunsalted buttersoftened at room temperature
¼cupheavy cream
⅛teaspoonground nutmeg
¾teaspoonsaltor to taste
¾teaspoonpepperor to taste
For optional tomato sauce
2Tablespoonsunsalted butter
1small shallotpeeled and thinly sliced
1garlic cloveminced
6 tomatoesdiced
3tablespoonsfresh parsleyfinely chopped, with additional for garnish
Salt and pepper to taste
Instructions
Preheat oven to 400°F. Line 2 baking sheets with parchment paper or a silicone liner.
Peel potatoes and cut into 1-inch pieces. Place them in a saucepan and fill with water enough to cover the potatoes. Bring to a boil, then simmer until the potatoes are tender, about 20 minutes. When tender, drain and transfer the potatoes to a large bowl.
Mash potatoes until completely smooth using a potato masher or potato ricer. While the potatoes are still warm, fold in egg yolks one at a time. Then, fold in softened butter and cream. Season with salt and pepper to taste, about ¾ teaspoon each or so, and nutmeg if desired.
Transfer mashed potatoes to a large piping bag fitted with a ½-inch star tip. Starting from the center, pipe into swirled mounds about 2-inches wide. Repeat until all potato is used - you should have enough for about 20 duchess potatoes. (See notes for piping if serving with sauce in center.)
Bake in the preheated 400°F oven until golden brown, about 20 minutes, rotating the baking sheets half-way through. Once ready, remove from the oven and use a spatula to carefully remove the potatoes from the baking sheet.
How to Make Tomato Sauce for Duchess Potatoes
Melt butter over medium heat in a large saucepan.
Add sliced shallots and cook until softened, stirring occasionally. Stir in garlic and cook until fragrant, about 30 seconds to 1 minute.
Add chopped tomatoes and cook until they start to break down in the pan, stirring occasionally, about 20-30 minutes. Stir in parsley and season with salt and pepper.
Spoon the sauce into the cavities of the cooked duchess potatoes as soon as they are ready.
Notes
Tomato sauce is optional, but it makes a great filling for duchess potatoes if you want to use it. Follow the steps for piping with a cavity at the center of the potatoes, then add the tomato sauce immediately after baking.
If you're making the duchess potatoes with a sauce, you can instead pipe them while leaving a space at the center. Begin by piping a small circle of potato, about 2-inches wide, on the prepared baking sheet. Around the edge of the circle, pipe 3 layers tall, creating a cavity in the center. Fill with desired sauce immediately after removing from the baking sheet.
Egg yolks are what help the duchess potatoes keep shape in the oven, so they are a necessary part of the recipe. However, you can otherwise customize your mashed potatoes in just about any way you'd like!
Any potato will work just fine for making this dish - Yukon gold and russet are good choices.
You can make duchess potatoes without a piping bag by cutting a "W" into one corner of a large plastic bag to mimic a star tip, or by forgoing the piping bag altogether and using a spoon to dollop out the potatoes. Of course, using a piping bag (makeshift or otherwise) will look the best.