Cheesy Root Vegetable Gratin Recipe tastes rich, creamy, and ultra-savory, with tender layers of roots tucked under a bubbling, golden cheese crust. It suits cozy family dinners, holiday tables, or any night when you want comfort food in about 1 hour 15 minutes from start to finish. I tested versions of this gratin so many times that my neighbors now greet me with “got leftovers?” instead of “hello.”

Why You Should Try This Cheesy Root Vegetable Gratin Recipe

This Cheesy Root Vegetable Gratin Recipe gives you all the comfort of scalloped potatoes with more flavor, color, and nutrients. The mix of sweet and earthy roots pairs with a garlicky cream sauce and plenty of melty cheese, so every bite tastes complex and satisfying.

It works as a vegetarian main or a hearty side, and it fits both weeknights and holidays. You can prep it ahead, bake it when you need it, and enjoy a dish that looks fancy but stays totally doable.

“This Cheesy Root Vegetable Gratin Recipe stole the show at dinner and tasted even better the next day, which almost never happens with side dishes. ★★★★★”

Ingredients You’ll Need

You can tweak this Cheesy Root Vegetable Gratin Recipe with what you have, but this combo hits the sweet spot of flavor and texture.

Root vegetables

2 medium russet or Yukon Gold potatoes, thinly sliced
- Yukon Golds hold shape and taste buttery. Russets turn softer and creamier.
2 medium sweet potatoes, thinly sliced
2 medium parsnips, thinly sliced
2 medium carrots, thinly sliced
1 small rutabaga or turnip, thinly sliced
1 small red onion or yellow onion, thinly sliced

Use a mandoline or a sharp chef’s knife so the slices stay about 1/8 inch thick. Thin slices cook evenly and soak up the cheesy cream.

Cheese and dairy

1 ½ cups shredded Gruyère cheese
- Use Swiss if you cannot find Gruyère.
1 cup shredded sharp cheddar cheese
- Pre-shredded works in a pinch, but block cheese melts smoother.
1 cup heavy cream
1 cup whole milk
- Use half-and-half instead of the cream and milk combo if that sits in your fridge already.
3 tablespoons unsalted butter

Flavor boosters

3 cloves garlic, minced
1 teaspoon kosher salt, plus more to taste
½ teaspoon black pepper
½ teaspoon smoked paprika or regular paprika
½ teaspoon dried thyme or 1 teaspoon fresh thyme leaves
¼ teaspoon ground nutmeg
2 tablespoons grated Parmesan cheese for topping
2 tablespoons chopped fresh parsley or chives for garnish

Pantry shortcuts and substitutions

Use a bag of mixed root vegetables from the produce section if you want to skip peeling and guessing amounts.
Swap in celeriac, beets, or extra carrots if you miss one of the roots listed.
Use all cheddar or all Gruyère if you prefer, just keep the total amount of cheese the same.
Use gluten free breadcrumbs on top if you want a little crunch and need a gluten free option.

Equipment list

9×13 inch baking dish or similar casserole dish
Mandoline slicer or sharp chef’s knife and cutting board
Large mixing bowl
Medium saucepan
Whisk
Aluminum foil
Oven mitts and a heat safe trivet

Tips & Tricks

Slice all roots to the same thin thickness so they cook evenly and turn tender at the same time.
Soak potato and sweet potato slices in cold water for 10 minutes, then dry them, to remove extra starch and keep the sauce from turning gluey.
Warm the cream and milk with garlic and spices before you pour it over the vegetables so the flavors blend and the gratin cooks more evenly.
Layer cheese between the vegetables, not just on top, so every scoop pulls up stretchy, melty bits.
Cover the dish with foil for the first part of baking so the roots soften, then uncover to brown the cheese.
Test doneness with a thin knife; it should slide through the center with no resistance.
Let the gratin rest 10 to 15 minutes after baking so the sauce thickens and slices hold together.
Use a baking sheet under the dish if it sits very full, since the cheesy cream can bubble over the sides.

How to Make Cheesy Root Vegetable Gratin Recipe

Prep the vegetables and oven

Heat the oven to 375°F. Grease your baking dish with a little butter or neutral oil.
Peel the potatoes, sweet potatoes, parsnips, carrots, and rutabaga. Slice them into thin rounds about 1/8 inch thick.
Place the potato and sweet potato slices in a bowl of cold water for 10 minutes, then drain and pat dry with clean towels. Keep the other roots on a tray or in a bowl.
Slice the onion into thin half moons and set aside.

Make the creamy cheese sauce

Add the butter to a medium saucepan and set it over medium heat.
Once the butter melts, add the minced garlic and cook 30 to 60 seconds until it smells fragrant but not browned.
Pour in the cream and milk, then whisk in salt, pepper, paprika, thyme, and nutmeg.
Heat the mixture until it steams and tiny bubbles form around the edges, then turn off the heat.
Stir in half of the Gruyère and half of the cheddar until they melt into the hot cream. Taste and adjust seasoning with a pinch more salt or pepper if needed.

Layer the gratin

Spread a thin layer of the warm cheese sauce on the bottom of the baking dish.
Arrange a layer of mixed root vegetable slices over the sauce, slightly overlapping them like shingles. Tuck in some onion slices.
Sprinkle a handful of the remaining Gruyère and cheddar over the vegetables.
Repeat layers of vegetables, onion, and cheese until you reach the top of the dish or run out of ingredients.
Pour the remaining cheese sauce evenly over the top, tilting the dish slightly so the sauce seeps down through the layers.
Sprinkle the Parmesan over the surface.

Bake to bubbly perfection

Cover the baking dish tightly with foil, tenting it slightly so the cheese does not stick.
Place the dish on a baking sheet and slide it into the oven. Bake 35 to 40 minutes until the vegetables start to soften.
Remove the foil and continue baking 20 to 25 minutes until the top turns deep golden and the edges bubble.
Check doneness by sliding a thin knife into the center; it should glide through without crunch.
Take the gratin out of the oven and let it rest 10 to 15 minutes. Sprinkle with chopped parsley or chives before serving.

What to Serve with Cheesy Root Vegetable Gratin Recipe

This Cheesy Root Vegetable Gratin Recipe pairs nicely with simple proteins like roasted chicken thighs, baked tofu, or seared pork chops. Add a crisp green salad with a tangy vinaigrette to cut through the richness. Steamed green beans, roasted Brussels sprouts, or sautéed spinach balance the creamy texture. Serve with sparkling water, flavored seltzer, or a big pitcher of iced tea for a family friendly spread.

Storage Options

Cool leftovers to room temperature, then cover the dish or transfer slices to airtight containers and refrigerate for up to 4 days.
Freeze individual portions in freezer safe containers or tightly wrapped slices for up to 2 months.
Reheat in a 350°F oven, covered, for 15 to 20 minutes from the fridge or 25 to 30 minutes from frozen, until hot in the center.
Use the microwave for quick single servings, then finish in a hot oven or under the broiler for a few minutes to crisp the top again.