Creamy Celeriac and Potato Gratin with a Toasted Hazelnut Crust Tips, FAQ & printable recipe

Tips for success

To ensure the best texture, avoid rinsing the potato slices after cutting them, as the natural starch is necessary to help thicken the cream as it bakes.

If you choose to prepare the slices ahead of time, keep them submerged in a bowl of cold water to prevent oxidation, then pat them thoroughly dry with a clean kitchen towel before layering them into the dish.

When adding the hazelnuts, try to crush them into varied sizes, from fine crumbs to larger pieces. This variety creates a more interesting texture and ensures that every bite has a slightly different, satisfying crunch.

If the hazelnuts are not pre-roasted, toast them in a dry skillet over medium heat for 3-5 minutes until fragrant before crushing them to add to the gratin.

Variations

• Herbed Breadcrumb Crust: Replace the hazelnuts with a mixture of panko breadcrumbs, fresh parsley, and a touch of lemon zest for a lighter, herb-forward crunch that brightens the overall flavor profile of the dish.
• Smoky Bacon Addition: Incorporate finely diced, rendered bacon between the layers of celeriac and potatoes to introduce a savory, smoky depth that complements the earthy notes of the root vegetables beautifully.

Storage and make-ahead

Fridge

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

Reheat

Reheat in a 350°F oven until warmed through or in the microwave in short bursts.

Cover any remaining gratin tightly with plastic wrap or transfer it to an airtight container once it has cooled to room temperature. It will maintain its quality for up to three days in the refrigerator.

When ready to serve again, ensure it is reheated thoroughly, as the creamy nature of the dish requires even warming to restore its original, luxurious consistency.

You can assemble the gratin up to 24 hours in advance, keeping it covered in the refrigerator before baking. If baking directly from the refrigerator, extend the initial cooking time by approximately 10 to 15 minutes to ensure the center reaches the proper temperature.

Add the hazelnut topping during the final 10 minutes of baking as instructed to maintain its optimal crunch.

Serving ideas

Serve the gratin while it is still warm, ideally alongside a fresh, crisp green salad with a light vinaigrette to balance the richness of the cream and cheese. The acidity of the salad dressing provides a perfect counterpoint to the earthy sweetness of the celeriac and the decadent, velvety texture of the baked potatoes.

This dish works beautifully as a sophisticated side for roasted meats or as a vegetarian main course when accompanied by a hearty vegetable dish. Use a large serving spoon to scoop portions, ensuring each serving includes a generous amount of the crispy hazelnut crust, the tender vegetable layers, and the thickened, flavorful cream at the bottom of the dish.

Frequently asked questions

Recipe card

Creamy Celeriac and Potato Gratin with a Toasted Hazelnut Crust

Prep 20 minCook 45 minRest 10 minTotal 1 h 15 minServes 6

Ingredients

• 500 g celeriac root, peeled and thinly sliced
• 500 g Yukon Gold potatoes, thinly sliced
• 450 ml heavy cream
• 3 garlic cloves, smashed
• 2 sprigs fresh thyme
• 1 bay leaf
• 180 g cave-aged Gruyère cheese, grated
• 50 g roasted hazelnuts, crushed
• 50 g cave-aged Gruyère cheese, grated

Instructions

1. Place the heavy cream, smashed garlic cloves, fresh thyme, and bay leaf into a large saucepan. Bring the mixture to a gentle simmer over medium heat, ensuring it does not boil over. Let the cream infuse with the aromatics for about five minutes to develop a deep, savory flavor profile before adding the vegetables.
2. Peel and slice the celeriac root and Yukon Gold potatoes into uniform 2mm discs using a mandoline for precision. Arrange the slices in the baking dish, alternating the celeriac and potatoes to create distinct, beautiful layers. Pour the warm, infused cream mixture over the vegetables, ensuring every layer is thoroughly coated for even cooking.
3. Distribute the 180g of grated Gruyère cheese evenly over the layered vegetables. Place the dish into a preheated oven at 375°F (190°C) and bake for 35 minutes. Carefully remove the dish, sprinkle the crushed roasted hazelnuts and the additional 50g of Gruyère over the top, then return to the oven for a final 10 minutes until the crust is golden and blistering.

Contains: milk, tree nuts, celery

Estimated nutrition per serving

Calories

420

Protein

12.5 g

Carbohydrates

28 g

Fat

31 g

Fiber

4.5 g

Sugar

3.5 g

Sodium

450 mg

Automatic estimate from the ingredient list, not laboratory-verified.