📝 About This Recipe
This quintessential comfort food features paper-thin slices of Yukon Gold potatoes bathed in a velvety, garlic-infused cream sauce and baked until golden-brown. Unlike its cousin, Potatoes Au Gratin, this classic scalloped version focuses on the pure, silky harmony of starch and dairy, accented by the earthy aroma of fresh thyme. It is a timeless side dish that transforms humble root vegetables into an elegant, melt-in-your-mouth masterpiece perfect for Sunday roasts or holiday gatherings.
🥗 Ingredients
The Potatoes
- 3 pounds Yukon Gold Potatoes (scrubbed and peeled)
- 1 tablespoon Unsalted Butter (softened, for greasing the baking dish)
The Cream Sauce (Roux Base)
- 4 tablespoons Unsalted Butter
- 1/4 cup All-Purpose Flour
- 1.5 cups Whole Milk (warmed slightly)
- 1.5 cups Heavy Cream (warmed slightly)
- 3 cloves Garlic (minced very fine)
- 1 tablespoon Fresh Thyme Leaves (stripped from the stem)
- 1.5 teaspoons Kosher Salt (plus more for seasoning layers)
- 1/2 teaspoon Black Pepper (freshly cracked)
- 1/8 teaspoon Nutmeg (freshly grated)
Aromatic Layering & Garnish
- 1/2 large Yellow Onion (sliced into paper-thin half-moons)
- 2 tablespoons Fresh Parsley (finely chopped for garnish)
👨🍳 Instructions
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1
Preheat your oven to 375°F (190°C). Generously grease a 9x13 inch ceramic or glass baking dish with 1 tablespoon of softened butter, ensuring you coat the corners well.
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2
Using a mandoline slicer or a very sharp chef's knife, slice the peeled potatoes into uniform rounds approximately 1/8-inch thick. Place them in a bowl of cold water to prevent browning while you prepare the sauce.
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3
In a medium saucepan over medium heat, melt the 4 tablespoons of butter. Once foaming, add the minced garlic and cook for 1 minute until fragrant but not browned.
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4
Whisk in the flour to create a roux. Cook, whisking constantly, for 2 minutes to remove the raw flour taste; the mixture should look slightly pale and bubbly.
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5
Slowly pour in the milk and heavy cream in a steady stream, whisking vigorously to prevent lumps from forming.
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6
Continue cooking the sauce over medium heat, whisking frequently, until it thickens enough to coat the back of a spoon (about 5-7 minutes). Do not let it reach a hard boil.
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7
Remove the sauce from heat. Stir in the kosher salt, cracked pepper, nutmeg, and fresh thyme leaves. Taste and adjust seasoning if necessary.
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8
Drain the potatoes and pat them thoroughly dry with kitchen towels. Excess water will make the sauce runny, so this step is crucial.
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9
Arrange one-third of the potato slices in the bottom of the prepared baking dish, overlapping them slightly like shingles. Scatter half of the thinly sliced onions over this layer.
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10
Pour one-third of the cream sauce evenly over the first layer of potatoes. Repeat the process: another third of potatoes, the remaining onions, and another third of the sauce.
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11
Add the final layer of potatoes in a neat, decorative pattern and pour the remaining sauce over the top. Press down gently with a spatula to ensure the sauce penetrates all layers.
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12
Cover the dish tightly with aluminum foil. Bake for 45 minutes. Covering prevents the top from burning while the potato centers soften.
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13
Remove the foil and continue baking for another 25-30 minutes. The top should be deeply golden brown and the sauce should be bubbling around the edges.
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14
Test for doneness by inserting a paring knife into the center; it should slide through the potatoes with zero resistance.
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15
Remove from the oven and let the dish rest for at least 10-15 minutes before serving. This allows the sauce to set and makes for cleaner slices. Garnish with fresh parsley before bringing to the table.
💡 Chef's Tips
Always use Yukon Gold potatoes for the best texture; they hold their shape better than Russets but are creamier than Red potatoes. To prevent the sauce from curdling, ensure your milk and cream are not ice-cold when adding them to the hot roux. If the top is browning too quickly after removing the foil, tent it loosely with the foil again for the final 10 minutes. For a hint of smoke, you can add finely diced sautéed pancetta between the layers. Dry the potato slices religiously—moisture is the enemy of a thick, velvety scalloped sauce.
🍽️ Serving Suggestions
Serve alongside a Garlic and Herb Crusted Prime Rib for the ultimate holiday feast. Pairs beautifully with a crisp, dry Chardonnay or a light Pinot Noir to cut through the richness. Accompany with a bright, acidic side like a Lemon-Arugula salad to balance the heavy cream. Excellent with honey-glazed ham and roasted green beans for a classic Sunday dinner.