Name: Sous Vide French-Style Mashed Potatoes (Pommes Purée)
Total time: 1 h 20 min
Cuisine: FrenchEurope
Ingredients: 2 pounds Yukon Gold potatoes peeled and sliced ¼ inch thick; 20 tablespoons (2½ sticks) unsalted butter; 1⅓ cups whole milk; Salt and white pepper

Why This Recipe Works

Pommes purées is a rich, smooth, velvety, and supremely satisfying French side dish that pairs well with pretty much everything—mushrooms, steak, chicken, scallops, lamb, you name it. We found that cooking the potatoes directly in milk and butter in a bag in the water bath concentrated the potato flavor and helped cook the potatoes evenly. All that was left to do was run the contents through a food mill, whisk it all together, and boom: decadent pommes purées.

Before You Begin

You can omit the final straining step, but the potatoes will be slightly less smooth and velvety. Be sure to double bag the potatoes to protect against seam failure. Potatoes have a tendency to float when placed in a sous vide water bath, which can lead to uneven cooking. Use weights to make sure the potatoes are fully immersed during cooking. For more about sous vide cooking, refer to our sous vide guide.

Instructions

Using sous vide circulator, bring water to 194°F/90°C in 7-quart container.

Rinse potatoes in fine-mesh strainer under cold running water until water runs clear. Drain potatoes well.

Place potatoes, butter, milk, and 1 teaspoon salt in 1-gallon zipper-lock freezer bag. Seal bag, pressing out as much air as possible. Place bag in second 1-gallon zipper-lock freezer bag and seal. Gently lower bag into prepared water bath, weight bag until potatoes are fully submerged, and then clip top corner of bag to side of water bath container, allowing remaining air bubbles to rise to top of bag. Reopen 1 corner of zipper, release remaining air bubbles, and reseal bag. Cover and cook for 45 minutes.

Drain potatoes in fine-mesh strainer set over large saucepan; place saucepan over low heat. Working in batches, transfer potatoes to hopper of food mill or potato ricer and process into saucepan. Using whisk, recombine potatoes and cooking liquid until smooth, 10 to 15 seconds (potatoes should almost be pourable). Strain potatoes through fine-mesh strainer into bowl, pressing on solids with ladle to extract as much as possible. Season with salt and pepper to taste. Serve immediately.