Parsnip and Celery Root Gratin

This Parsnip and Celery Root Gratin is a deeply comforting creamy, cheesy baked dish with tender layers of root vegetables and golden, crispy breadcrumbs on top. It's a seasonal twist on a classic potato gratin, aka the perfect starchy side for the holidays, or just a cozy cold-weather dinner.

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A serving of parsnip and celery root gratin on a white plate with a serving in the baking dish, showing the creamy, layered texture inside and the crispy top, accompanied by vintage utensils and a sprig of thyme.

If you’re into creamy, cheesy bakes with golden, crispy tops, this one’s for you. I’ve always had a soft spot for anything au gratin—there’s just something about those rich, bubbling layers that I can’t resist!

Over the years, I’ve created lots of different versions (linked below), but this Parsnip and Celery Root Gratin might be one of my favorites. It’s a seasonal spin on my classic potato gratin—aka Dauphinoise potatoes.

I love the way earthy celery root and sweet parsnips come together, adding a subtle sweetness and nuttiness that plays so well with the Gruyere.

If you’re new to these underrated root veggies, try them in this celery root and parsnip puree too—they really shine in cozy, cold-weather dishes like this!

A side view of a thick slice of parsnip and celery root gratin on a white plate showing the distinct creamy layers of the root vegetables, with a crispy breadcrumb topping and vintage cutlery alongside.

What is a Gratin?

The word gratin comes from the French term gratter, meaning “to scrape” or “to grate.” In culinary terms, a gratin typically refers to a dish baked and topped with a browned crust of cheese, breadcrumbs, or both!

It’s all about that bubbly, crisp, golden layer that forms during baking. While gratins are commonly made with potatoes, they can be made with just about anything, from vegetables to pasta to seafood and more.

The technique is classic, but the ingredients are endlessly adaptable!

Want more cozy au gratin recipes? Try my cheesy cauliflower au gratin, this rich and savory fennel + onion gratin, or this kale gratin that gets devoured every time I serve it.

Why This Recipe Works

Uses peak fall and winter produce—perfect for holiday season.
Crispy breadcrumbs give a beautiful golden crunch to contrast the soft vegetables.
It's a perfect make-ahead side dish that actually improves after resting.

Ingredient Notes

Parsnips – Parsnips look like white carrots, and they’re one of my favorite cold-weather root vegetables. They have a mild, sweet flavor with a slightly nutty undertone, and their texture becomes beautifully tender and creamy when baked.

Celery Root (Celeriac) – This knobby, underrated root has a subtle celery-like flavor and a starchy texture that makes it ideal for gratins and purees. Don’t be intimidated by its rough exterior—it peels easily with a knife and rewards you with loads of flavor.

Gruyere Cheese – Nutty, melty, and slightly funky, Gruyere is the gold standard for a gratin like this. But if you don’t have it on hand, Swiss cheese, Fontina, Muenster, or Raclette all make great stand-ins—as long as they melt well.

Heavy Cream – Rich and luscious, cream is the base of the sauce. Don’t skimp here—it’s what makes the gratin, well, gratin.

Breadcrumbs – A final layer of breadcrumbs on top gets golden and crispy in the oven, giving that signature texture contrast. Panko works well too.

*Find the full ingredient list in the recipe card below!

Helpful Equipment

8x8" baking dish or medium gratin dish
Sharp knife or mandolin
Cutting board
Vegetable peeler
Mixing bowl
Whisk
Aluminum foil

Step by Step Instructions

Thinly sliced white parsnips on a wooden cutting board with shredded cheese in a white bowl and a white baking dish filled with layered vegetables and cheese visible in the background, all set against a white parchment paper surface.

A bowl of creamy white béchamel sauce with a metal whisk, alongside a small green plate containing nutmeg and black pepper, all arranged on white parchment paper - the foundation ingredients for a gratin.

Preheat the oven to 400°F.
Butter the bottom and sides of a medium gratin dish or an 8x8" baking dish.
Peel and slice the parsnips and celery root into thin, even slices.

Pro Tip: A mandolin or a food processor with a slicing blade is your best friend here, but a sharp knife will work too. Aim for uniform slices—they’ll cook evenly and give the gratin a better overall texture.

Layer the vegetables in the baking dish, alternating between parsnip and celery root slices. After every few layers, sprinkle a little bit of Gruyere, saving a handful for the top.
In a small bowl, whisk together the heavy cream, salt, pepper, and a pinch of nutmeg. Pour this over the layered vegetables. Press down slightly to help the cream seep into all the layers and remove any air pockets.

A white rectangular baking dish filled with assembled but unbaked parsnip and celery root gratin, topped with a light breadcrumb and cheese mixture, showing the layered vegetable slices visible at the edges.

A close-up of the golden-brown, crispy-topped parsnip and celery root gratin fresh from the oven, showing the bubbly, browned breadcrumb crust in a white ceramic baking dish resting on a cork trivet.

Sprinkle breadcrumbs evenly over the top, then cover with foil.
Bake for one hour, then remove the foil and bake for an additional 15–25 minutes, or until the top is deeply golden and bubbling at the edges.

Test for doneness by piercing the center with a knife. It should glide through without resistance. If the vegetables aren’t fully tender, keep baking until they are.
If the top starts to get too brown before the vegetables are done, loosely cover with foil to prevent over-browning.
Let rest for at least 10 minutes before serving. This gives the gratin time to settle and set.

A close-up of a slice of parsnip and celery root gratin on a white ceramic plate, highlighting the layers of vegetables bound with creamy sauce, topped with the golden-brown crust and garnished with fresh thyme.

Tips for Success

Use a mandolin to make thin, even slices. This ensures the vegetables cook at the same rate.
Peel celery root with a knife. It has a tough, irregular skin and a regular peeler usually isn’t up to the task.
Don’t skip the resting time. Letting the gratin sit helps everything hold together, making it easier to serve and more flavorful.
You can assemble the gratin up to a day in advance and bake it off when ready. Or bake, cool, and gently reheat before serving.

Serving Suggestions

This Parsnip and Celery Root Gratin is right at home on a holiday table, especially at Thanksgiving, Christmas or any winter dinner party.

It pairs nicely with hearty main dishes like Dijon herb-crusted rack of lamb, a whole roasted beef tenderloin, or an elegant Italian-style roasted turkey.

It’s also perfect with simpler classics like herb-roasted fish, this easy pan seared filet mignon for two, or a succulent whole roasted chicken.

An extreme close-up of a forkful of the parsnip and celery root gratin, showcasing the tender vegetable layers and creamy sauce, with the remaining portion visible on a rustic ceramic plate.

How to Store and Reheat

Store leftovers tightly covered in the refrigerator for up to 3 days. Reheat in a 350°F oven until warmed through and re-crisped on top. Avoid microwaving if possible—it tends to make the texture a little mushy.

This dish doesn’t freeze well due to the cream, so enjoy it fresh!

FAQ

Can I prep this in advance?

Yes! You can assemble the gratin ahead of time, refrigerate it, and then bake it off when you're ready. Just add 10–15 minutes to the bake time if starting from cold.

What’s the best cheese substitute for Gruyere?

Any good melty cheese will work—Fontina, Raclette, Muenster, or Swiss are great choices.

Can I add garlic or herbs?

Definitely. A few cloves of thinly sliced garlic or sprigs of thyme tucked into the layers would be delicious.

Can I use milk instead of cream?

Whole milk or half and half can be used in a pinch, but the texture will be looser and less rich.

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