Potatoes Au Gratin Recipe: How to Get That Golden Crust

There’s something undeniably magical about a perfectly executed potatoes au gratin. That moment when you break through the golden, crispy top layer to reveal the tender, creamy potato slices beneath is culinary perfection. After years of testing and refining my recipe, I’m excited to share my foolproof method for creating the ultimate potatoes au gratin with that coveted golden crust that will have everyone at your table asking for seconds.

This classic French dish (known as “gratin dauphinois” in France) has earned its place as a staple on holiday tables and Sunday dinners, but it deserves a spot in your regular rotation. With my straightforward approach, you’ll master this impressive side dish that pairs beautifully with everything from a simple roast chicken to an elaborate beef tenderloin. Let’s dive into creating the perfect potatoes au gratin that balances creamy interior with that irresistible golden crust.

How to Make Potatoes Au Gratin

Quick Overview

Potatoes au gratin are essentially thinly sliced potatoes baked in a rich, creamy sauce until tender inside and beautifully golden on top. What makes this dish so captivating is the perfect harmony between the velvety smooth sauce that envelops each potato slice and the delightfully crisp, caramelized top layer.

My version features two key elements that elevate it above typical recipes: a perfectly balanced cream mixture infused with garlic and herbs that creates the ideal sauce consistency, and a strategic baking method that ensures both perfectly tender potatoes and that signature golden crust. The sauce is enriched with two types of cheese – Gruyère for its nutty depth and Parmesan for sharp flavor and browning capability.

The Ingredients I Use to Bring My Potatoes Au Gratin to Life

For the cream mixture:

• 2 cups heavy cream
• 1 cup whole milk
• 3 garlic cloves, minced
• 1 tablespoon of fresh thyme leaves, or 1 teaspoon if using dried thyme
• 1 teaspoon kosher salt
• 1/2 teaspoon freshly ground black pepper
• 1/4 teaspoon freshly grated nutmeg
• 1 bay leaf

For the potatoes and assembly:

• 3 pounds Yukon Gold potatoes (about 6-7 medium-large potatoes)
• 2 tablespoons unsalted butter, softened (for greasing the baking dish)
• 8 ounces Gruyère cheese, grated (about 2 cups)
• 1/2 cup freshly grated Parmesan cheese
• 2 tablespoons fresh chives, finely chopped (for garnish, optional)

Special equipment:

• A mandoline slicer or a very sharp chef’s knife
• 9×13 inch baking dish (preferably ceramic or glass)
• Heavy-duty aluminum foil

Step-by-Step Instructions

Step 1: Prepare Your Ingredients and Equipment

1. Preheat your oven to 350°F (175°C) with a rack positioned in the middle.
2. Thoroughly butter your baking dish, making sure to coat the bottom and sides completely. This prevents sticking and adds flavor to the outer edges of your gratin.
3. Wash your potatoes well, but do not peel them. The skins of Yukon Gold potatoes are thin and contain flavor and nutrients. If you strongly prefer peeled potatoes, you may peel them, but the intact skin helps the slices hold their shape better.

Step 2: Infuse the Cream Mixture

1. In a medium saucepan, mix together the heavy cream, whole milk, minced garlic, fresh thyme, kosher salt, black pepper, nutmeg, and a bay leaf.
2. Place over medium-low heat and bring to a gentle simmer, stirring occasionally. Be careful not to let it boil over.
3. Once it reaches a simmer, reduce the heat to low and let it infuse for 10 minutes, stirring occasionally. The cream should be steaming but not boiling.
4. After 10 minutes, remove from the heat and fish out the bay leaf. Allow the cream mixture to cool slightly while you slice the potatoes.

Step 3: Slice the Potatoes

1. Using a mandoline set to approximately 1/8-inch thickness (or a very sharp knife and careful, even cutting), slice the potatoes into thin, uniform rounds. Consistency in thickness is key for even cooking.
2. As you slice, place the potato rounds in a large bowl of cold water. This prevents them from oxidizing (turning brown) and removes some of the excess starch, which helps prevent a gluey texture in the final dish.
3. Once all potatoes are sliced, drain them thoroughly in a colander and pat dry with paper towels. Excess water will dilute your cream mixture and prevent proper browning.

Step 4: Layer the Gratin

1. Place about 1/3 of the potato slices in the bottom of your buttered baking dish, arranging them in slightly overlapping rows. Think of it as creating three distinct layers of potatoes.
2. Pour about one-third of the cream mixture over the first layer of potatoes, then top with one-third of the grated Gruyère cheese.
3. Repeat with another 1/3 of the potatoes, another 1/3 of the cream mixture, and another 1/3 of the Gruyère.
4. For the final layer, arrange the remaining potatoes, pour over the remaining cream mixture, and top with the last of the Gruyère plus all of the Parmesan cheese. The Parmesan on top is crucial for developing that beautiful golden crust.

Step 5: Bake to Perfection

1. Cover the baking dish tightly with aluminum foil, ensuring it’s sealed well around the edges. This traps steam and helps cook the potatoes evenly.
2. Put the covered dish into the preheated oven and bake for 45 minutes. During this covered phase, the potatoes will cook through and absorb the cream.
3. After 45 minutes, carefully remove the foil (be cautious of hot steam) and increase the oven temperature to 425°F (220°C).
4. Place the uncovered dish back in the oven and bake for another 25–30 minutes, until the top is richly golden and bubbling at the edges. For a more golden crust, you can broil it during the last 2–3 minutes—just keep a close eye to avoid burning.
5. To test for doneness, insert a knife into the center of the gratin – it should slide in easily with no resistance, indicating the potatoes are completely tender.

Step 6: Rest and Serve

1. Remove the potatoes au gratin from the oven and let them rest for at least 15 minutes before serving. This resting period is crucial as it allows the cream to be absorbed and the layers to set up, making it easier to serve neat portions.
2. Just before serving, sprinkle with fresh chives if desired, which adds a pop of color and fresh flavor.
3. Use a sharp knife to cut into portions and a spatula to lift each serving intact from the dish.

What to Serve Potatoes Au Gratin With

Potatoes au gratin pair beautifully with a variety of main dishes. Here are some ideal companions:

Meat pairings:

• Roasted beef tenderloin or prime rib: The rich, creamy potatoes complement the robust flavors of beef.
• Herb-roasted chicken: The simple, clean flavors of roast chicken allow the potatoes to shine.
• Glazed ham: For holiday meals, this classic pairing never disappoints.
• Grilled lamb chops: The gratin’s creaminess balances the distinctive flavor of lamb.

Lighter accompaniments to balance the meal:

• Roasted asparagus or green beans: Their fresh, green flavors cut through the richness.
• Simple arugula salad with lemon vinaigrette: The peppery greens and acidic dressing provide a welcome contrast.
• Roasted Brussels sprouts with balsamic glaze: Their slight bitterness complements the creamy potatoes.
• Steamed broccoli with lemon zest: For a simple, bright side that balances the meal.

Wine pairings:

• Chardonnay: A medium-bodied, lightly oaked Chardonnay echoes the buttery notes in the gratin.
• Pinot Noir: Its acidity and medium body stand up to the richness without overwhelming it.
• Côtes du Rhône: These French blends naturally complement this French-inspired dish.

Top Tips for Perfecting Potatoes Au Gratin

1. Choose the right potatoes: Yukon Golds are ideal because they have enough starch to thicken the sauce slightly, but remain creamy rather than mealy when cooked. Russets can work, but tend to break down more, while waxy red potatoes don’t absorb the cream as well.
2. Slice thickness matters: Aim for consistent 1/8-inch slices. Too thin, and they’ll dissolve into the cream; too thick, and they won’t cook through properly. A mandoline is invaluable for this task.
3. Don’t skip the warming step for the cream: Infusing the cream mixture with aromatics adds depth of flavor, while the warm cream begins to cook the potatoes slightly as you build the layers.
4. Consider your cheese options: While Gruyère is traditional for its excellent melting properties and nutty flavor, good substitutions include Comté, Emmental, or even a combination of Swiss and sharp cheddar in a pinch.
5. Don’t rush the process: The covered baking time ensures the potatoes cook through, while the uncovered time is essential for developing that golden crust. Taking shortcuts will result in either undercooked potatoes or insufficient browning.
6. Troubleshooting common issues:

• If your gratin seems too liquid after baking, you may have used too much cream, not patted the potatoes dry enough, or removed it from the oven too soon
• If potatoes aren’t tender, they were likely sliced too thick or need more time covered
• If the top isn’t browning well, your oven temperature might be off; try using the broiler for the last few minutes

1. Make it ahead: You can assemble the entire dish up to 24 hours in advance and refrigerate it, covered. Add 10-15 minutes to the initial covered baking time if cooking directly from the refrigerator.

Storing and Reheating Tips

Potatoes au gratin actually improve in flavor overnight as the ingredients meld together, making it an excellent make-ahead dish.

Short-term storage:

• Allow leftover potatoes au gratin to cool to room temperature (but not longer than 2 hours for food safety).
• Cover the dish with plastic wrap or place portions into airtight containers.
• Refrigerate for up to 4 days.

Freezing options:

• Potatoes au gratin can be frozen, though the texture of the cream may change slightly upon thawing.
• For best results, freeze in individual portions in airtight containers.
• Label with the date and contents, and use within 2 months.
• Allow to thaw completely in the refrigerator before reheating (usually overnight).

Reheating methods:

1. Oven method (best for preserving texture):

• Preheat oven to 350°F (175°C).
• If reheating the entire dish, cover with foil and bake for 20-25 minutes, then uncover and bake for an additional 5-10 minutes to re-crisp the top.
• For single servings, transfer to an oven-safe dish, cover with foil, and bake for 15–20 minutes until fully heated.

1. Microwave method (quick but less ideal):

• Place the individual portion on a microwave-safe plate.
• Cover with a damp paper towel to help retain moisture.
• Heat on 70% power for 1-2 minutes, then check and continue in 30-second intervals until heated through.
• Note that the crispy top won’t remain crisp with this method.

1. Make it crispy again:

• If you’ve used the microwave, you can place the reheated portion under a broiler for 1-2 minutes to re-crisp the top.
• Be vigilant, as it can go from golden to burnt very quickly.

Revitalizing tips:

• If your reheated potatoes seem dry, drizzle a small amount of warm cream over the top before the final heating phase.
• A sprinkle of freshly grated cheese before the final reheating can help refresh the crust.
• Fresh herbs added after reheating bring back some of that just-made brightness.

Mastering potatoes au gratin with its perfect golden crust is a culinary achievement that will serve you well for years to come. While it may seem like a special occasion dish, I encourage you to make it part of your regular cooking repertoire. There’s something deeply satisfying about transforming simple ingredients—potatoes, cream, cheese—into something so luxurious. The crispy, golden top giving way to creamy, tender layers beneath creates a textural experience that elevates any meal from ordinary to memorable.

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