Name: Roasted Garlic Potatoes au Gratin Recipe
Prep time: 30 min
Cook time: 1 h 10 min
Total time: 1 h 40 min
Cuisine: Western
Ingredients: 8-9 medium starchy potatoes (about 1.2kg), thinly sliced; 1 head garlic, roasted; 1 cup (250 ml) heavy cream / double cream; 1/4 cup (60 ml) whole milk; 1 tablespoon unsalted butter; 1 tsp fresh thyme leaves (or 1/3 tsp dried thyme); 1/4 tsp nutmeg; 1/2 cup (40g) grated parmesan cheese, divided; 2 cups (about 220g) shredded Gruyère or mozzarella cheese; Salt and pepper to taste; Fresh chives, for garnish

Roasted Garlic Potatoes au Gratin is the ultimate comfort food that combines silky layers of potatoes, creamy sauce, and the irresistible depth of roasted garlic. Every bite is laced with gooey melted cheese, fragrant thyme, and just enough nutmeg to keep things interesting. Whether you’re aiming to impress at a holiday dinner or simply want to treat yourself on a quiet night in, this dish brings a touch of rustic elegance to any table. It’s one of those recipes everyone will ask for — and you’ll find yourself returning to it again and again.

Roasted Garlic Potatoes au Gratin Recipe - Recipe Image

Ingredients You’ll Need

The magic of Roasted Garlic Potatoes au Gratin lies in its simple yet thoughtfully chosen ingredients. Each one has a crucial job, from the creamy layers to the golden, bubbly top, and together they create that unforgettable harmony of flavor and texture.

Potatoes: Choose starchy potatoes such as Russets or Yukon Golds, thinly sliced, for tender layers that absorb the rich sauce beautifully.
Garlic: One whole head, roasted until caramelized, infuses the cream with a sweet, mellow depth you just can’t get from raw garlic.
Heavy cream: This brings the luscious, velvety texture that makes every forkful indulgent.
Whole milk: Lightens the cream sauce just enough while keeping it rich and pourable.
Unsalted butter: Used for both greasing and flavor, butter gives the dish a luxurious mouthfeel.
Fresh thyme: Offers earthy, aromatic notes that balance the richness; dried thyme works in a pinch.
Nutmeg: A pinch is all you need to add warmth and complexity to the sauce.
Parmesan cheese: Sharp and salty, parmesan deepens the flavor and helps create that signature golden crust.
Gruyère or mozzarella cheese: Gruyère is classic for its nutty melt, while mozzarella gives a wonderful pull — use your favorite or what’s on hand.
Salt and pepper: Essential for drawing out the natural flavors of every layer.
Fresh chives: A final flourish for color and a subtle oniony bite that wakes up the whole dish.

How to Make Roasted Garlic Potatoes au Gratin

Step 1: Roast the Garlic

Preheat your oven to 375°F (190°C). Take a whole head of garlic, slice off the top to expose the cloves, drizzle with olive oil, sprinkle with a pinch of salt, and wrap it tightly in aluminum foil. Bake for about 30 minutes, until the cloves are soft and golden. Roasting tames the garlic’s intensity, leaving you with a mellow, sweet paste that’s absolutely key in authentic Roasted Garlic Potatoes au Gratin.

Step 2: Prepare the Baking Dish

While your garlic transforms in the oven, grease a 9×13-inch (23×33 cm) baking dish with butter. This not only prevents sticking but adds another subtle layer of richness as the potatoes bake.

Step 3: Slice the Potatoes

Peel and thinly slice your potatoes — a mandoline slicer is your best friend here for even, delicate slices. Uniform thickness means the potatoes cook evenly and soak up every drop of that luscious cream.

Step 4: Layer the Potatoes

Stand the potato slices upright (nestled together like little potato dominoes) in your prepared dish. Don’t worry about making it perfect — rustic is lovely here. Keep layering until the dish is full and the potatoes are ready for their creamy bath.

Step 5: Make the Cream Mixture

In a saucepan, gently warm the heavy cream, milk, a tablespoon of butter, half of your parmesan, thyme, nutmeg, salt, and pepper. Stir just until the butter melts and everything is well combined. Keep a close eye and don’t let it boil; the goal is just to meld the flavors.

Step 6: Add the Roasted Garlic

Once the garlic is cool enough to handle, squeeze those jammy cloves out and mash them into a smooth paste. Stir this roasted garlic into the warm cream mixture — you’ll see the sauce become fragrant and slightly golden, ready to transform your potatoes.

Step 7: Assemble and Bake (First Round)

Pour the creamy, garlicky mixture evenly over the potatoes, ensuring every slice gets a generous coating. Cover the dish tightly with foil and bake for 40 minutes. This first round of baking lets the potatoes soften and soak up all that flavor.

Step 8: Add Cheese and Bake Again

Remove the foil and sprinkle on the shredded Gruyère (or mozzarella) along with the remaining parmesan. Return the dish to the oven, uncovered, for another 30 minutes. By the end, you’ll have bubbling, golden cheese blanketing perfectly tender potatoes — the classic finish for Roasted Garlic Potatoes au Gratin.

Step 9: Rest, Garnish, and Serve

Let the gratin cool for a few minutes before slicing, which helps the layers set. Sprinkle generously with fresh chopped chives just before serving. Then, dig in and enjoy the show-stopping combination of creamy, cheesy, garlicky goodness.

How to Serve Roasted Garlic Potatoes au Gratin

Garnishes

A simple sprinkle of fresh chives is the traditional finishing touch, adding a burst of color and delicate onion flavor that cuts through the richness. If you’re feeling fancy, a little extra parmesan or a few fresh thyme leaves on top can elevate the look even further.

Side Dishes

Roasted Garlic Potatoes au Gratin is wonderfully versatile as a side. It pairs beautifully with roasted chicken, holiday turkey, hearty steaks, or even vegetarian main courses. For balance, serve alongside something fresh — maybe a crisp green salad or steamed vegetables to lighten the meal.

Creative Ways to Present

Serve the gratin in individual ramekins for a dinner party-worthy presentation, or use a cookie cutter to create neat squares for an elegant buffet. You can even spoon out rustic scoops for a casual family dinner. No matter how you plate it, this dish always looks golden and irresistible.

Make Ahead and Storage

Storing Leftovers

Leftover Roasted Garlic Potatoes au Gratin keep beautifully for up to 3 days in an airtight container in the fridge. The flavors deepen overnight, making next-day helpings an even bigger treat, whether straight from the dish or packed for lunch.

Freezing

You can absolutely freeze this dish — let it cool completely, then wrap tightly or store in a freezer-safe container. For best results, freeze before adding the final layer of cheese. When ready to serve, thaw overnight in the refrigerator, add your cheese topping, and bake until bubbly and hot.

Reheating

Reheat leftovers in the oven at 350°F (175°C) until warmed through and the top crisps up again. For a quick fix, you can use the microwave, but the oven is your best bet for restoring that glorious melt and golden crust.

FAQs

Can I use a different type of potato?

Absolutely! Starchy varieties like Yukon Gold or Russet potatoes work best for Roasted Garlic Potatoes au Gratin. Waxy potatoes will be firmer and less likely to absorb the sauce, but can still be used if you prefer a different texture.

What can I substitute for heavy cream?

Whole milk with a little extra butter can be swapped in, but for that ultra-creamy consistency, heavy (double) cream is ideal. You could also try half-and-half, though the result will be slightly lighter.

Is it possible to make this dish vegetarian or gluten free?

Yes! As written, Roasted Garlic Potatoes au Gratin is naturally vegetarian. To ensure it’s gluten-free, double-check that your cheeses and any added flavorings are certified gluten-free.

Can I assemble the gratin ahead of time?

Definitely. Assemble the dish (up through pouring on the cream sauce), cover, and keep in the fridge for up to 24 hours before baking. This is perfect for prepping ahead, especially during busy holiday cooking.

Why is my gratin watery?

A watery result often means the potatoes weren’t sliced thinly enough or the dish needed a little longer in the oven. Be sure to use starchy potatoes and slice them as evenly as possible for that creamy, cohesive finish you want in classic Roasted Garlic Potatoes au Gratin.

Final Thoughts

If you’re looking for a showstopper side or just craving the ultimate comfort food, give Roasted Garlic Potatoes au Gratin a try. It’s the kind of dish that guarantees happy sighs with every bite, and I promise you’ll be asked for the recipe! Gather your ingredients, invite some friends or family over, and let this creamy, cheesy, garlicky masterpiece steal the show on your table.