Celeriac & Potato Gratin with Creamy Herb Sauce
A velvety, luxurious gratin made with thinly sliced potatoes and earthy celeriac layered in a fragrant, creamy sauce with garlic, herbs, and a touch of cheese. Baked until golden and bubbling, this dish is cozy, elegant, and perfect for holiday dinners, special occasions, or a Mediterranean-inspired comfort meal.
⏱ Time
Prep: 15 minutes
Cook: 55–65 minutes
Total: 70–80 minutes
🥘 Ingredients
For the Gratin
2 medium potatoes, peeled and thinly sliced
1 medium celeriac (celery root), peeled and thinly sliced
1 small onion, thinly sliced (optional)
1 cup grated cheese (Gruyere, Parmesan, mozzarella, or a mix)
1 tbsp fresh thyme or 1 tsp dried
1 tbsp fresh parsley, chopped (optional for topping)
Salt & black pepper to taste
For the Creamy Sauce
1 ½ cups heavy cream or half-and-half
¾ cup milk
2 cloves garlic, minced
1 tbsp olive oil
½ tsp nutmeg
1 tsp salt
½ tsp black pepper
(Optional: Replace half the cream with Greek yogurt for a lighter Mediterranean twist.)
🍽 Instructions
1. Prepare the vegetables
Peel the potatoes and celeriac.
Slice them thinly (about ⅛ inch) using a knife or mandoline.
Keep slices uniform to ensure even baking.
2. Make the creamy sauce
In a saucepan over medium heat, put olive oil.
Add garlic and sauté 30 seconds.
Pour in the cream + milk.
Add salt, pepper, and nutmeg.
Heat until warm (don’t boil), then remove from heat.
3. Layer the gratin
Preheat oven to 375°F (190°C).
Grease a baking dish.
Add a layer of potatoes, sprinkle with salt, pepper, thyme, and cheese.
Add a layer of celeriac, season lightly again, and sprinkle cheese.
Continue layering until vegetables are used.
Pour the warm creamy sauce evenly over everything.
Finish with a layer of cheese on top.
4. Bake
Cover with foil and bake 35 minutes.
Remove foil and bake 20–30 more minutes until:
✔ Golden brown on top
✔ Bubbly around edges
✔ Knife slides easily through layers
5. Rest & serve
Let gratin rest 10 minutes before slicing—this helps it set.
💡 Tips
Slice very thinly: Thin layers cook evenly and create a silky texture.
Don’t skip nutmeg: It enhances the celeriac’s natural flavor.
Add protein: Top with crispy chickpeas or serve with grilled chicken or fish.
Make it lighter: Swap some cream for milk or Greek yogurt.
Make it vegetarian: Use only cheeses made with vegetarian rennet.
❄️ Storage
Refrigerate: 3–4 days
Reheat: Cover and warm at 350°F (175°C) for 15–20 minutes
Freezer: Not recommended (cream-based sauces can split)
❓ frequently Asked Questions FAQs
Can I use sweet potatoes instead?
Yes — for a sweeter, deeper flavor. Mix 50% sweet potato + 50% celeriac.
Can I make this ahead?
Yes — assemble fully, refrigerate unbaked for up to 24 hours, then bake when ready.
Can I skip the cheese?
Absolutely — it will still be creamy and delicious.
Do I have to peel celeriac?
Yes — its outer skin is tough and fibrous.
🧮 Nutritional Information
Calories ~320 kcal
Carbs 28 g
Protein 7 g
Fat 20 g
Sodium 380 mg