Why You’ll Love Roasted Garlic Potatoes au Gratin Recipe
It combines the richness of creamy potatoes au gratin with the sweet, mellow depth of roasted garlic.
The layers of potato and cheese yield a satisfyingly creamy interior and a crisp, golden top.
You can assemble it ahead and bake when ready.
It works beautifully as a side dish or a vegetarian main when paired with a salad.
Leftovers reheat well and still retain much of their texture and flavor.
Ingredients
(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)
8–9 medium starchy potatoes (≈ 1.2 kg), thinly sliced
1 head garlic, top cut off (to roast)
1 cup heavy cream / double cream (≈ 250 ml)
¼ cup (60 ml) whole milk
1 tablespoon unsalted butter (plus extra for greasing)
1 tsp fresh thyme leaves (or ⅓ tsp dried)
¼ tsp nutmeg
Salt and pepper, to taste
½ cup (40 g) grated Parmesan cheese, divided
2 cups (≈ 220 g) shredded Gruyère or mozzarella (for melting)
Fresh chives, for garnish (optional)
Directions
Preheat the oven to 190 °C (≈ 375 °F).
Roast the garlic: place the garlic head (top trimmed) on a piece of foil, drizzle with olive oil and season lightly with salt. Wrap in foil and roast for about 30 minutes, until the cloves are soft and golden.
Grease a 23×33 cm (9×13 in) baking dish with butter.
Peel and thinly slice the potatoes evenly (a mandoline is ideal for consistent thickness).
Arrange the potato slices upright and tightly layered in the prepared baking dish.
In a saucepan over medium heat, combine the heavy cream, milk, butter, half the Parmesan, thyme, nutmeg, salt, and pepper. Heat until the butter is melted and the mixture is smooth (do not boil).
Squeeze the roasted garlic cloves out of their skins, mash them into a paste, and stir into the cream mixture.
Pour the warm garlic-cream sauce evenly over the potatoes, coating all the layers.
Cover the dish tightly with foil and bake for 40 minutes.
Remove the foil, sprinkle shredded Gruyère and the remaining Parmesan over the top.
Return the dish to the oven and bake uncovered for another 30 minutes, until the top is golden and bubbly and the potatoes are tender.
Let the gratin rest a few minutes before serving. Garnish with chopped chives, if using.
Servings and timing
Yield: 8 servings
Prep time: 30 minutes
Cook time: 1 hour 10 minutes
Total time: 1 hour 40 minutes
Variations
Use different cheeses: Try cheddar, Havarti, or Fontina instead of Gruyère.
Lighter version: Use half cream and half milk, or all milk for a thinner, less rich sauce.
Add vegetables: Thinly sliced onions or leeks can be layered with the potatoes for extra flavor.
Non-vegetarian version: Add cooked bacon or pancetta between layers for a smoky twist.
Time-saving tip: Parboil the potato slices or partially roast them beforehand to shorten baking time.
Storage/Reheating
Refrigerator: Store in an airtight container for up to 3 days.
Reheating: Warm in a 160–170 °C oven until heated through, or microwave individual portions (note: topping may soften).
Freezing: Not ideal — texture may change, but it can be frozen in portions and reheated slowly.
FAQs
Can I assemble the gratin ahead of time?
Yes — prepare the full dish, cover, and refrigerate up to a day in advance. Bake just before serving.
Can I substitute the roasted garlic with fresh garlic?
You can, but the flavor will be sharper. Roasted garlic adds a mellow, sweet depth.
What type of potatoes work best?
Use starchy or all-purpose potatoes like Russets or Yukon Gold for the best texture.
What if my top browns too quickly?
Cover loosely with foil once the top is golden to prevent overbrowning while the interior cooks through.
Can I reduce the cream to make it lighter?
Yes — replace some of the cream with milk, but the gratin will be less rich and creamy.
Can I skip the nutmeg?
Yes — it adds subtle warmth, but it’s optional.
Is this dish vegetarian?
Yes, as written — just ensure your cheese and butter are vegetarian-friendly.
How do I get even potato slices?
Use a mandoline or carefully slice with a sharp knife for uniform thickness.
Will the gratin firm up as it cools?
Yes — the sauce thickens upon cooling, making it easier to slice and serve.
Can I use mozzarella instead of Gruyère?
Yes — mozzarella will give a melty, stringy texture. It’s milder in flavor but still delicious.
Conclusion
Roasted Garlic Potatoes au Gratin is a rich and deeply satisfying dish that transforms humble ingredients into an elegant comfort food. The sweet intensity of roasted garlic elevates the classic gratin, making it perfect for family dinners or festive gatherings. Serve it alongside roast meats or a crisp green salad for a well-rounded meal.
