Pommes Duchesse (Duchess Potatoes)
Duchess potatoes, or Pommes de Terre Duchesse in French, are made of a purée of mashed potato, egg yolk, and butter that is pressed out in a piping bag or hand-moulded into a variety of shapes and baked at a high temperature until brown. Other potato dishes like Pommes Dauphiné, which integrates Pâte à Choux for fluffy fried potato puffs, might be made using this combination as a base.
To be clear, Pommes Duchesses’ popularity goes beyond its looks. The eggs give the potatoes more structure and flavour while also allowing them to keep their shape when piped. For this recipe, I decided on a combination of two yolks and one whole egg, which, when baked, helps the potatoes bubble up, their surface browning and crisping slightly, giving a thin shell that contrasts wonderfully with the creamy mashed potato core. It resembles a combination of meringue and a salty mashed potato soufflé.
For some individuals, pipping each potato slice would be a bit excessive, and I don’t disagree. But on special occasions, like during the holidays or at a dinner party, you might want to go all out. In those cases, this recipe is ideal. I created the recipe so that it could be used to make either individual piped servings or a slightly more unpolished but still attractive family-style casserole. I add a little heavy cream to the recipe to increase creaminess without sacrificing structural stability.
Instructions for Piping and Browning Potatoes
- For precisely shaped potatoes, pipe the potatoes first, chill them in the refrigerator for an hour or overnight, then brush with butter and bake
- To give the potatoes even more browning, you can also egg wash them.
- Use a natural-bristle brush instead of a silicone-bristle one. Butter is held more securely by natural bristles.
- To prevent the potatoes from clinging to the bottom and to make clean-up easier, line your baking pan with parchment paper or a silicone baking sheet.
- 3 pounds of Yukon Gold potatoes, peeled and cut into small bits
- Salt and freshly ground black pepper
- ⅓ cup (80ml) heavy cream
- Pinch freshly grated nutmeg
- 4 tablespoons (90g) unsalted butter, melted
- 1 large egg plus 2 yolks, lightly beaten
- Non-stick cooking spray (for piped individual portions only)
- Melted clarified butter for brushing (optional)
- Preheat the oven to 450 °F (230 °C) with the rack in the middle position. Put the potatoes in a medium (3 quarts (3.41 l)) pot and fill it with a few inches of cold water. Add 2 teaspoons of salt to the water. Cook for about 10 minutes, or until the potatoes are soft and hardly budge when punctured with a paring knife.
- Drain the potatoes in a strainer when they have finished cooking. Place the pot over low heat and add the potatoes once more. For about a minute, let them release steam.
- Mash the potatoes with 2 tablespoons of butter until all the butter has been mixed. As you continue to mash the potatoes, add the heavy cream, nutmeg, and black pepper. After combining everything, season with salt to taste. Stir in the beaten egg mixture, being careful not to over-mix the potatoes.
- To make individual portions: Line a rimmed baking sheet with parchment paper and gently coat it with non-stick cooking spray. Fill a pastry bag with the potato mixture and a 1/2-inch star tip. Hold the full pastry bag at an 80° angle, apply constant downward pressure, and pipe a 3-inch-wide mound in a circular motion. To end the piping, remove the pastry tip and swirl it away. Pipe the remaining 12 sections approximately 2 inches (5.08 cm) apart. If used, lightly cover the sections with clarified butter, being careful not to ruin the piped design.
- Grease a 2-quart baking dish and place it on a rimmed baking sheet for a casserole. 2/3 of the potato mixture should be placed in the prepared baking dish. Fill the remaining 1/3 of the pastry bag with a 1/2-inch star tip. Using a flexible or offset spatula, smooth the potato mixture into an even layer in the baking dish. Pipe the remaining potato on top, holding the pastry bag at an angle of 80° and exerting constant downward pressure to make little mounds in an even ornamental design. If used, lightly cover chunks with clarified butter, being careful not to undo the piped design.
- Put in the oven and bake until it is golden brown, or 10–15 minutes for individual portions and about 25 minutes for the casserole version, ensuring to rotate the baking sheet halfway through baking.