This is the only way we're making potatoes from now on.
Ingredients
- unsalted butter: 3 Tbsp (softened, divided)
- yellow onions (1 1/4 pounds total onions) : 5 cups (thinly sliced)
- heavy whipping cream: 2 cups
- garlic (2 large cloves): 2 Tbsp (thinly sliced)
- 1/2 teaspoons fresh thyme leaves: 1 piece (for garnish)
- fresh rosemary: 0.5 tsp (chopped)
- black pepper: 0.25 tsp
- 1/2 teaspoons kosher salt: 2 piece (divided)
- 1/2 pounds medium Yukon Gold potatoes, scrubbed (about 8): 2 piece
- 1/2 ounces Parmesan, finely shredded, divided (about 2/3 cup): 1 piece
- ounces extra-sharp white Cheddar cheese, shredded (about 1 1/2 cups): 6 piece
Metric Conversion
Stages of cooking
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Gather all ingredients. Preheat the oven to 450 degrees F (230 degrees C). Grease the bottom and sides of an 18x13-inch sheet pan with 1 tablespoon of the butter. Dotdash Meredith Food Studios
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Melt remaining 2 tablespoons butter in a large nonstick skillet over medium. Add onions; cook, covered, stirring occasionally, until onions are soft and translucent, 5 to 7 minutes. Dotdash Meredith Food Studios
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Reduce heat to medium-low and continue cooking, uncovered, stirring occasionally, until onions become very soft and brown, 30 to 35 minutes. Remove from heat. Dotdash Meredith Food Studios
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While onions cook, bring cream, garlic, thyme, rosemary, pepper, and 1/2 teaspoon salt to a simmer in a small saucepan over medium; immediately remove from heat. Dotdash Meredith Food Studios
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Thinly slice potatoes on a mandoline into 1/8-inch-thick rounds. Dotdash Meredith Food Studios
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Arrange half of the potato slices (about 3 1/2 cups) into a single, overlapping layer on the prepared baking sheet so that bottom of the sheet is not showing. Dotdash Meredith Food Studios
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Sprinkle evenly with 1 teaspoon salt, caramelized onions, and 1/3 cup Parmesan. Dotdash Meredith Food Studios
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Top with remaining potato slices in a single overlapping layer, and sprinkle with remaining 1 teaspoon salt. Dotdash Meredith Food Studios
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Pour hot cream mixture evenly over potatoes. Cover baking sheet tightly with foil. Dotdash Meredith Food Studios
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Bake in the preheated oven until potatoes are tender when pierced with a fork, 20 to 25 minutes. Dotdash Meredith Food Studios
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Carefully remove foil, scrape off any potato or garlic slices sticking to it, and sprinkle potatoes with Cheddar and remaining 1/3 cup Parmesan. Dotdash Meredith Food Studios
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Return to the oven and bake, uncovered, until browned and crusty on top, rotating the pan halfway through, 15 to 20 minutes. Dotdash Meredith Food Studios
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Sprinkle with more thyme leaves and serve immediately. Dotdash Meredith Food Studios
