Recipes Side Dishes Potato Dishes Mashed Potatoes French Onion Mashed Potatoes 5.0 (2) 2 Reviews These creamy mashed potatoes combine sweet caramelized onions, nutty Gruyère, and a golden, cheesy broiled top. By Craig Ruff Craig Ruff Craig Ruff is a food editor and recipe developer at Food & Wine. He joined People Inc. as a fellow before moving into the test kitchen as a full time assistant, where he cross-tested and developed countless recipes for Food & Wine and other People Inc. food brands. Food & Wine's Editorial Guidelines Published on August 31, 2026 Save Rate PRINT Share Close Credit: Food & Wine / Caley Ellenburg / Food Stylist Julian Hensarling / Prop Stylist Abby Armstrong Active Time: 1 hr 15 mins Total Time: 1 hr 40 mins Servings: 6 Jump to recipe Slowly caramelizing the onions develops deep sweet-savory flavor, while dry sherry loosens the browned bits from the skillet and adds complexity.Using both Yukon Gold and russet potatoes produces a mash with the buttery flavor of Golds and the lighter, fluffier texture of russets.Scooping the mash into mounds before broiling yields plenty of surface area for Gruyère and Parmesan cheese to melt and brown on top. This mash-up of two cozy classics channels the complexity of French onion soup into creamy mashed potatoes. Caramelized onions, nutty Gruyère, Parmesan, thyme, and sherry build the signature flavor profile, while a mix of Yukon Gold and russet potatoes gives the mash both buttery richness and a fluffy texture. The onions cook low and slow until jammy, then get deglazed with sherry to loosen the fond from the skillet. The potatoes are passed through a ricer for the smoothest texture, then enriched with butter, egg yolks, and Gruyère. The caramelized onions are gently folded into the mash, but then the mix, instead of being spread into a single layer, is scooped into mounds and topped with more cheese. That extra surface area helps the cheese brown under the broiler, creating a golden top while the potatoes stay creamy underneath. It’s a dressed-up take on classic mashed potatoes, complex enough for a dinner party but familiar enough to serve with a simple roast or steak. Why use both Yukon Gold and russet potatoes? The two varieties bring different qualities to the mash. Yukon Golds are moderately starchy with a buttery flavor and a dense, creamy texture, while russets are higher in starch and lower in moisture, so they produce a lighter, fluffier mash. Using both gives the potatoes enough richness and body without becoming heavy or gluey. Do I need a potato ricer to make these mashed potatoes? No, but a ricer produces a smooth, fluffy mash without overworking the starch in the potatoes. If you don’t have one, use a potato masher and stop as soon as the potatoes are smooth, or pass them through a fine mesh strainer. The 7 Best Potato Ricers, According to Our Tests Notes from the Food & Wine Test Kitchen Slice the onions as evenly as possible so they caramelize at the same rate; a mandoline makes quick work of the 5 cups needed here.Drain the potatoes thoroughly before ricing them. Excess water can loosen the mixture and make it harder for the scoops to hold their shape.Sprinkle the cheese directly over each potato mound rather than across the entire baking dish; this preserves the mounded shape while creating golden, cheesy tops. This recipe was developed by Marianne Williams; the text was written by Craig Ruff. Keep Screen Awake Ingredients 2 tablespoons neutral oil (such as canola or vegetable) 1 1/2 pounds sweet onions, thinly sliced (about 5 cups) 2 teaspoons kosher salt, divided 2 tablespoons dry sherry 1 1/2 pounds Yukon Gold potatoes, peeled and cut into 2-inch pieces 1 1/2 pounds russet potatoes, peeled and cut into 2-inch pieces 1 large garlic clove, grated (about 1 teaspoon) 6 tablespoons unsalted butter, cubed and at room temperature 2 large egg yolks 10 ounces Gruyère cheese, shredded (about 2 1/2 cups), divided 2 ounces Parmesan cheese, grated (about 1/2 cup), divided 1 teaspoon fresh thyme leaves, plus more for garnish Cracked black pepper Directions Heat oil in a large skillet over medium-high. Add onions and 1 teaspoon salt; cook, stirring occasionally, until onions begin to soften, about 10 minutes. Reduce heat to medium-low; cook, stirring occasionally, until onions are very soft and deep golden brown, 45 to 55 minutes. Stir in sherry, scraping bottom of skillet to loosen browned bits; cook over medium-low, stirring often, until liquid has evaporated, about 2 minutes. Remove from heat. While onions cook, place Yukon Gold and russet potatoes in a large saucepan; add salted water to cover by 1-inch. Bring to a boil over high. Reduce heat to medium; cook until potatoes are fork-tender, 15 to 20 minutes. Drain well into a colander. Pass potatoes through a potato ricer back into the same saucepan. Add garlic, butter, and remaining 1 teaspoon salt to riced potatoes; stir until butter is melted. Fold in egg yolks, caramelized onions, 8 ounces (about 2 cups) of the Gruyère, 1 1/2 ounces (about 6 tablespoons) Parmesan, and thyme until evenly distributed. Preheat oven to broil with rack about 6 inches from heat source. Using an ice cream scoop, scoop potato mixture into mounds in a large broiler-safe baking dish. Sprinkle each mound evenly with remaining 2 ounces (about 1/2 cup) Gruyère and remaining 1/2 ounce (about 2 tablespoons) Parmesan. Broil until potatoes are heated through and cheese is melted and golden brown, 8 to 10 minutes. Garnish with more thyme and cracked black pepper. Serve immediately. Make ahead The onions can be caramelized up to three days in advance and refrigerated in an airtight container; reheat them before folding them into the potatoes. Cook this recipe and more in the MyRecipes app. Get the App Save Rate Print Loading shell for RecipesUgcThreaded1 Vue component in Globe.