Roasted Garlic Potato au Gratin combines thinly sliced starchy potatoes arranged upright in a baking dish, bathed in a creamy sauce infused with roasted garlic paste, fresh thyme, nutmeg, and Parmesan, then topped with bubbly Gruyère or mozzarella for a golden, cheesy crust.
You’ll love this elegant side dish because the roasted garlic delivers sweet, savory depth that elevates the classic creamy potatoes au gratin into irresistible comfort food perfect for holidays or dinner parties.
Ingredients
- 8–9 medium starchy potatoes (about 2.6 lb), thinly sliced
- 1 large head of garlic, top cut off
- 1 cup heavy cream
- ¼ cup whole milk
- 1 tablespoon unsalted butter, plus extra for greasing
- 1 teaspoon fresh thyme (or ⅓ teaspoon dried thyme)
- ¼ teaspoon nutmeg
- ½ cup grated Parmesan cheese, divided
- 2 cups shredded Gruyère or mozzarella cheese
- Salt and black pepper, to taste
- Fresh chives, for garnish
Instructions
- Preheat oven to 375°F. Roast garlic: cut top off head, drizzle with oil, salt, wrap in foil, bake 30 minutes until soft. Cool slightly.
- Grease 9×13-inch dish. Thinly slice peeled potatoes (mandoline ideal); arrange upright in layers.
- Heat cream, milk, butter, half the Parmesan, thyme, nutmeg, salt, and pepper until butter melts do not boil.
- Mash roasted garlic into paste; stir into cream mixture. Pour evenly over potatoes; cover tightly with foil.
- Bake 1 hour 15 minutes. Remove foil, top with Gruyère/mozzarella and remaining Parmesan.
- Bake uncovered 15 minutes until cheese bubbles golden and potatoes are tender.
- Rest 5–10 minutes; garnish with chives.
Tips for Success
- Roast garlic until deeply golden for maximum sweetness.
- Use mandoline for uniform thin slices that cook evenly.
- Arrange potatoes upright for pretty presentation and even sauce distribution.
- Don’t boil cream sauce to prevent separation.
- Let rest for clean slicing.
Delicious Variations
- Add crumbled bacon between layers.
- Swap Gruyère for sharp cheddar.
- Mix in caramelized onions.
- Top with panko breadcrumbs for crunch.
- Use sweet potatoes for twist.
Frequently Asked Questions
Can it be made ahead?
Yes, assemble and bake up to 1 day ahead; reheat covered at 350°F.
Vegetarian?
Naturally vegetarian.
Gluten-free?
Yes, no flour needed.
Make dairy-free?
Use coconut cream and vegan cheeses.
Storage time?
Refrigerate airtight 3-4 days; reheat gently.
Print
Roasted Garlic Potato au Gratin
- Total Time: 135 minutes
- Yield: 8-10 servings 1x
Description
Thinly sliced starchy potatoes arranged upright in creamy sauce infused with roasted garlic paste, fresh thyme, nutmeg, and Parmesan, topped with bubbly Gruyère for golden cheesy crust.
Ingredients
8–9 medium starchy potatoes (about 2.6 lb), thinly sliced
1 large head of garlic, top cut off
1 cup heavy cream
¼ cup whole milk
1 tablespoon unsalted butter, plus extra for greasing
1 teaspoon fresh thyme (or ⅓ teaspoon dried thyme)
¼ teaspoon nutmeg
½ cup grated Parmesan cheese, divided
2 cups shredded Gruyère or mozzarella cheese
Salt and black pepper, to taste
Fresh chives, for garnish
Instructions
Preheat oven to 375°F. Roast garlic: cut top off head, drizzle with oil, salt, wrap in foil, bake 30 minutes until soft. Cool slightly.
Grease 9×13-inch dish. Thinly slice potatoes; arrange upright in layers.
Heat cream, milk, butter, half the Parmesan, thyme, nutmeg, salt, and pepper until butter melts. Mash roasted garlic into paste; stir into cream. Pour over potatoes; cover with foil.
Bake 1 hour 15 minutes. Remove foil, top with Gruyère and remaining Parmesan. Bake uncovered 15 minutes until golden. Rest 5–10 minutes; garnish with chives.
Notes
Use starchy potatoes (russet/Yukon gold) for best texture.
Arrange potato slices upright for restaurant-style presentation.
Roast garlic until very soft for maximum flavor.
Let rest before serving for clean slices.
Make ahead: Assemble day before, bake when needed.
- Prep Time: 30 minutes
- Cook Time: 105 minutes
- Category: Side Dish
- Method: Baking
- Cuisine: French-American
Nutrition
- Serving Size: 1/8 recipe
- Calories: 320
- Sodium: 380
- Fat: 20
- Saturated Fat: 12
- Carbohydrates: 28
- Fiber: 3
- Protein: 10
Keywords: roasted garlic potatoes au gratin, creamy garlic scalloped potatoes, cheesy potato gratin, holiday potato casserole, upright potato gratin
