Cheesy Root Vegetable Gratin

This Cheesy Root Vegetable Gratin recipe might be one of my absolute favorites for fall and winter. It’s a great variation from the typical potato gratin. I know it’s a lot of peeling and slicing, but if you have a mandoline it’s makes the process so much easier. Plus, after you’re done slicing the vegetables, the rest of the dish is very easy to put together.

I love the subtly sweet and earthy flavors of this combination of root vegetables mixed together with the savory and salty shredded cheese, garlic, thyme, and cream. It’s the perfect side dish to any thanksgiving, holiday or any cozy meal .

How to make this Cheesy Root Vegetable Gratin

Ingredients

unsalted butter
sweet potatoes
parsnips
beets
heavy cream
Parmesan cheese
fresh thyme
garlic
gruyere cheese
salt and pepper to taste

Process

Preheat oven
Grease baking dish with butter.
Slice sweet potato, parsnips and beets into very thin rounds (using a mandoline is easiest) and transfer each vegetable to its own bowl.
Pour cream over each sweet potatoes and parsnips, and beets.
Top each bowl of sliced vegetables with some grated Parmesan and some minced thyme. Season each bowl generously with salt and pepper and toss together until all vegetable slices are well coated.
Pour remaining cream into the greased baking dish and sprinkle with Parmesan and garlic.
Grab a stack of sweet potatoes and line them standing up on a bias, at the top of the baking dish.
Follow the sweet potatoes with a row of parsnips, followed by a row of beets.
Repeat with the remaining sweet potatoes, parsnips and beets, creating 6 rows of root vegetables.
Season top of gratin with salt, pepper and sprinkle of remaining Parmesan.
Cover with foil and bake until vegetables are soft.
Uncover gratin and top with shredded gruyere.
Place gratin back into oven, uncovered, and continue to bake until vegetables are fork tender, cheese has melted and the top has lightly browned.
Finish with a sprinkle of fresh thyme leaves. Serve.

A baking sheet with sliced root vegetables on it. — Slice all of your root vegetables. A mandoline works great for this!

Bowls of root vegetables with cream and cheese. — Add each type of sliced vegetables into glass bowls and pour cream, parmesan, and salt and pepper over them.

A buttered oval baking dish on a surface. — Butter the baking dish.

A buttered baking dish with a layer of cream, parmesan, and garlic. — Add cream, parmesan and garlic to cover the bottom.

A baking dish full of sliced root vegetables to make a root vegetable gratin. — Add stacks of root vegetables in lines and top with a sprinkling of parmesan and salt and pepper.

A baking dish covered with tin foil to go into the oven. — Cover with foil and bake.

A baking dish with root vegetable gratin. — Remove from oven and unwrap.

Root vegetable gratin with shredded cheese on top ready to go back into the oven. — Add some shredded Gruyere on top and bake in the oven until the cheese is melty and brown.

FAQs

Why do I bake this dish covered first, then uncover it?

Covering this dish in the beginning will allow the vegetables to soften without drying the dish out. Once the vegetables get to a good point, uncovering them will allow the top of the gratin brown and crisp up, while allowing some of the excess liquid to thicken/evaporate.

Can I prep this dish ahead of time?

Yes! This dish can be made up to a day ahead of time and refrigerated, tightly wrapped in foil. When ready to bake, just place the covered gratin in the oven, adding about an extra 5-7 minutes of baking time to the dish (covered).

Just know that if you prep this dish ahead of time, you run the risk of the beets bleeding from sitting in the cream. This won’t effect the flavor at all, but it’ll change the look of this dish.

I didn’t make the cheesy root vegetable gratin ahead of time and my beets still bled. Why?

The culprit was most likely the amount of cream/liquid used. We made sure to scale back on the amount of cream used to toss with the beets as well as the cream that sits in the bottom of the baking dish.

You really want to make sure the sliced beets are just barely coated in liquid to ensure they don’t dry out while baking. You also want to make sure the bottom layer of your baking dish is just coated with a thin layer of cream and sprinkled with Parmesan. The amount of cream used may vary just a little bit, depending on the surface area of the baking dish you’re using, so it’s best to eyeball this.

Why are there ranges for the number of each vegetable to use?

We add a small range for each vegetable because not all 3 quart baking dishes are oval and we encourage you to use what you have on hand (which would change the amount of surface area there is).

This plus the fact that the thickness of the sliced vegetables, the size of each vegetable themselves, and the degree of the bias in which the sliced vegetables are placed into the baking dish will all vary slightly from person to person, effecting the number of vegetables needed.

If there is a range from the number of vegetables to use, how did you calculate the nutrition facts?

The nutrition facts are based on the lowest number vegetables in each range in the ingredient list.

Tips and Tricks for Success

Ensure all the vegetables are coated in cream so they don’t dry out. The beets should just be barely coated in cream because too much cream coating will result in them bleeding through the dish.
The foil should be tightly wrapped around the baking dish to allow the dish to steam a little and for the vegetables to get tender before uncovering it.
Wear gloves when handling beets to prevent them from staining your hands. If you do stain your hands, wash them with a blend of baking soda and warm water and vigorous rub them together. You may need a couple rounds of this process to completely remove the stains.
Keeping the slices as uniform in thickness as possible will greatly help even cooking throughout the gratin.
Using a mandoline will not only ensure even thickness, but will also reduce the prep time. If you don’t have a mandoline a very sharp knife is the next best thing we recommend.

A close up of cheesy root vegetable gratin with a spoon.

Variations for Cheesy Root Vegetable Gratin

Chives, green onion, sage, and rosemary or a combination of herbs make a great alternative to the fresh thyme.
Shredded fontina, Swiss, comté, gouda, and mild cheddar all make great cheese alternatives for gruyere.
Whole milk or half and half can be used in place of cream, although there will be more liquid pooled in the bottom of the gratin after it’s baked.
Turnips and rutabaga make great root vegetable alternatives for any of the three used in this recipe.

This Cheesy Root Vegetable Gratin is seriously not to be missed! It’s a cozy and delicious side dish to any meal. We personally love to serve it alongside this Citrus Dry Brine Turkey, our Standing Rib Roast, our Pork Belly Porchetta, and our Oven Baked Chicken Thighs.

If you’re looking for other delicious thanksgiving or holiday side dishes, you can head on over to our Holiday Headquarters for some of our favorite ones! Enjoy!