Roasted Garlic Potatoes au Gratin

Why You’ll Love Roasted Garlic Potatoes au Gratin Recipe

This dish combines tender potatoes with a velvety cream sauce and perfectly melted cheese for a comforting and satisfying bite every time. Roasting the garlic first adds a deep, slightly sweet flavor that elevates the entire dish without overpowering it.

You’ll love how impressive it looks when served, with beautifully layered potatoes and a golden crust on top. Despite its elegant presentation, it’s simple enough for a weeknight dinner and special enough for holidays or gatherings. It pairs wonderfully with roasted meats, chicken, or even as a standout vegetarian main.

Ingredients

(Tip: You'll find the full list of ingredients and measurements in the recipe card below.)

8–9 medium starchy potatoes (about 1.2 kg), thinly sliced
1 large head garlic, top cut off
1 cup (250 ml) heavy cream or double cream
¼ cup (60 ml) whole milk
1 tablespoon unsalted butter, plus more for greasing the baking dish
1 teaspoon fresh thyme leaves or ⅓ teaspoon dried thyme
¼ teaspoon nutmeg
½ cup (40 g) grated parmesan cheese, divided
2 cups (about 220 g) shredded Gruyère or mozzarella cheese
Salt and pepper to taste
Fresh chives, for garnish

Directions

Preheat your oven to 375°F (190°C).

Start by roasting the garlic. Cut the top off the head of garlic to expose the cloves. Place it on a piece of aluminum foil, drizzle with olive oil, and season with a pinch of salt. Wrap tightly in the foil and roast in the oven for about 30 minutes, or until the cloves are soft and golden. Let it cool slightly, then squeeze the garlic out of the skins and mash into a smooth paste.

While the garlic is roasting, grease a 9x13-inch (23x33 cm) baking dish.

Peel and thinly slice the potatoes. For evenly thin slices, a mandoline slicer works best. Stack the slices and arrange them upright in the prepared baking dish, layering them tightly until the dish is full.

In a saucepan over medium heat, combine the heavy cream, milk, butter, half of the grated parmesan, thyme, nutmeg, salt, and pepper. Heat gently until the butter melts and everything is well combined. Do not allow the mixture to boil.

Stir the roasted garlic paste into the warm cream mixture until smooth and fully incorporated.

Pour the creamy garlic mixture evenly over the layered potatoes. Cover the dish tightly with foil and bake for 1 hour and 15 minutes.

Remove the foil, sprinkle the shredded Gruyère or mozzarella and the remaining parmesan over the top, and return the dish to the oven uncovered. Bake for an additional 15 minutes, or until the cheese is melted, bubbly, and golden brown, and the potatoes are fork tender.

Allow the dish to rest for a few minutes before serving. Garnish with freshly chopped chives.

Servings and timing

Servings: 8 servings

Prep time: 30 minutes
Cooking time: 2 hours
Total time: 2 hours 30 minutes

Calories per serving: 416 kcal

Variations

For a deeper flavor, add thinly sliced onions or caramelized shallots between the potato layers.

Swap Gruyère for sharp cheddar for a stronger, more pronounced cheese flavor.

Add crispy cooked bacon pieces between layers for a smoky twist.

For a lighter version, substitute part of the cream with additional milk, though the texture will be slightly less rich.

A sprinkle of breadcrumbs mixed with a little melted butter on top before the final bake can create an extra crispy crust.

Storage/Reheating

Store any leftovers in an airtight container in the refrigerator for up to 3 days.

To reheat, cover with foil and warm in a 350°F (175°C) oven until heated through. For individual portions, you can use a microwave, though reheating in the oven helps maintain the creamy texture and crisp top.

This dish can also be assembled a day in advance and refrigerated before baking. Let it sit at room temperature for about 20–30 minutes before placing it in the oven.

FAQs

Can I make this dish ahead of time?

Yes, you can assemble the entire dish ahead and refrigerate it before baking. Allow it to sit at room temperature briefly before baking as directed.

What type of potatoes work best?

Starchy potatoes such as Russet or Yukon Gold work best because they become tender and creamy when baked.

Do I have to roast the garlic?

Roasting the garlic is highly recommended because it creates a sweet, mellow flavor that blends beautifully into the cream sauce.

Can I freeze potato au gratin?

You can freeze it after baking, but the texture may change slightly upon reheating due to the cream. For best results, freeze in airtight containers and reheat gently.

How do I know when the potatoes are done?

Insert a knife or fork into the center. If it slides in easily, the potatoes are fully cooked.

Can I use only mozzarella?

Yes, mozzarella will work well and provide a gooey texture, though it has a milder flavor than Gruyère.

Why are my potatoes still firm?

They may have been sliced too thick or not baked long enough. Thin, even slices are key to proper cooking.

Can I add other herbs?

Absolutely. Rosemary or parsley can complement the flavors nicely.

What can I serve with this dish?

It pairs beautifully with roasted chicken, beef, pork, or even a fresh green salad for balance.

How can I make the top extra golden?

Broil the dish for 2–3 minutes at the end of baking, watching closely to prevent burning.

Conclusion

Roasted Garlic Potatoes au Gratin is a timeless comfort dish that delivers creamy layers of flavor with every bite. The roasted garlic adds depth and warmth, while the golden cheese topping provides the perfect finishing touch. Whether served at a holiday feast or a cozy family dinner, this dish is sure to become a favorite at your table.