Cheesy Root Vegetable Gratin is a cozy, comforting dish that brings together tender slices of root veggies like potatoes, carrots, and parsnips, all baked in a creamy cheese sauce until golden and bubbly. The mix of earthy vegetables with melted, gooey cheese makes this gratin a perfect side or even a main for chilly days.
I love making this gratin when I want something warm and satisfying but still a little special. The smell of the veggies roasting and the cheese melting always fills the kitchen with the kind of warmth that makes you want to stay inside and relax. One tip I have is to slice the veggies evenly so they cook at the same rate and the layers bake perfectly together.
This dish goes great alongside a simple green salad or roasted chicken, but honestly, I’ve been known to eat it straight from the baking dish because it’s just that good. It’s a great way to enjoy seasonal root vegetables without any fuss, and it’s always a hit at family dinners or holiday gatherings. I find it brings a nice cozy vibe to the table that everyone appreciates.
Key Ingredients & Substitutions
Root Vegetables: Potatoes, carrots, parsnips, and sweet potatoes create different textures and flavors here. If you want, swap parsnips for turnips or rutabaga—you’ll still get a nice depth of flavor.
Gruyère Cheese: Gruyère melts beautifully and adds a subtle nuttiness. If unavailable, try Swiss cheese, Fontina, or even sharp cheddar for a sharper taste.
Heavy Cream: This makes the gratin rich and creamy. For a lighter option, use half-and-half or mix milk with a bit of melted butter.
Thyme: Fresh thyme adds a lovely herbal note that works well with root veggies. You can use dried thyme but use less since dried herbs are more concentrated.
How Can I Get Perfectly Tender and Golden Root Vegetables?
Getting the veggies just right means slicing and layering carefully so they cook evenly and soak up the creamy sauce.
- Slice Evenly: Use a mandoline or sharp knife to slice vegetables about 1/8-inch thick. This helps them cook at the same speed.
- Layer Neatly: Arrange veggies tightly, alternating types for even cooking and a pretty look.
- Cover While Baking: Baking covered with foil for the first 40 minutes traps steam, softening the veggies.
- Finish Uncovered: Removing foil for the last bake browns the cheese and crisps the top. Broil briefly if you want extra golden crunch, but watch closely!
Equipment You’ll Need
- 9×13-inch baking dish – I recommend this size because it fits all the veggies comfortably and bakes evenly.
- Mandoline or sharp knife – helps you slice the vegetables evenly, so they cook uniformly.
- Mixing bowl – for stirring the cream, garlic, thyme, salt, and pepper; keeps everything organized.
- Aluminum foil – to cover the dish during the initial baking step, sealing in steam and softening the vegetables.
- Cheese grater – for shredding the Gruyère and Parmesan cheeses, making cheese layer smooth and even.
Flavor Variations & Add-Ins
- Swap Gruyère for sharp cheddar or fontina for different cheesy flavors. Cheddar gives a sharper, more tangy taste.
- Add sautéed onions or garlic in the cream mixture for extra flavor and aroma.
- Mix in cooked bacon bits or pancetta for a salty, smoky twist, perfect for non-vegetarians.
- Layer in sliced apples or pears for a sweet contrast that pairs well with the cheese and root vegetables.
Cheesy Root Vegetable Gratin
Ingredients You’ll Need:
Vegetables:
- 2 large potatoes, peeled and thinly sliced
- 2 large carrots, peeled and thinly sliced
- 2 large parsnips, peeled and thinly sliced
- 1 large sweet potato, peeled and thinly sliced
Cheese and Cream:
- 2 cups grated Gruyère cheese (or a mix of Gruyère and Parmesan)
- 2 cups heavy cream (or half-and-half for a lighter version)
Flavorings and Others:
- 2 garlic cloves, minced
- 1 tsp fresh thyme leaves, plus extra for garnish
- Salt and freshly ground black pepper to taste
- 2 tbsp unsalted butter (for greasing the baking dish)
How Much Time Will You Need?
This recipe takes about 20 minutes to prepare, including peeling and slicing the vegetables. Baking time is about 1 hour, with the dish covered for the first 40 minutes and then uncovered for 20-25 minutes to brown and bubble. Allow 10 minutes to rest before serving. In total, you’ll need roughly 1 hour and 30 minutes from start to finish.
Step-by-Step Instructions:
1. Preheat and Prepare the Dish:
Start by preheating your oven to 375°F (190°C). Generously butter a large oval or rectangular baking dish to keep the gratin from sticking and add extra flavor.
2. Mix the Cream and Flavorings:
In a mixing bowl, stir together the heavy cream, minced garlic, fresh thyme leaves, salt, and pepper. This creamy mixture will soak into the vegetables, adding a lovely rich flavor.
3. Layer the Vegetables:
Arrange the thin slices of potatoes, carrots, parsnips, and sweet potatoes in the prepared dish. You can lay them in neat rows or an overlapping circular pattern, alternating types to create a pretty and colorful layered effect.
4. Add Cream and Cheese:
Pour the cream mixture evenly over the vegetables, pressing down gently to make sure it seeps through the layers. Then sprinkle 1 ½ cups of the grated cheese evenly over the top. Save the remaining cheese for later.
5. Bake Covered:
Cover the dish tightly with aluminum foil and bake for 40 minutes. This traps steam to soften the vegetables while cooking them through.
6. Bake Uncovered for a Golden Top:
Remove the foil, sprinkle the reserved cheese on top, and bake uncovered for an additional 20-25 minutes. The cheese should turn golden brown and bubbly, and the vegetables should be tender when tested with a fork.
7. Optional Broil:
For extra browning and a crispy cheese crust, broil the gratin for 2-3 minutes at the end. Watch carefully to prevent burning!
8. Rest and Garnish:
Take the gratin out of the oven and let it rest for about 10 minutes. This helps it set slightly for easier serving. Garnish with a few fresh thyme sprigs before enjoying.
9. Serve and Enjoy:
Dish up your delicious, creamy, and cheesy root vegetable gratin as a hearty side or even as a satisfying vegetarian main course—perfect for warming up any mealtime.
Can I Use Frozen Vegetables for This Gratin?
Fresh is best for this recipe because frozen vegetables release more water and may become mushy. If you must use frozen, thaw and pat them very dry before assembling, but expect a slightly different texture.
Can I Make This Dish Ahead of Time?
Absolutely! Assemble the gratin and refrigerate it covered for up to 24 hours before baking. When ready, bake as directed, adding a few extra minutes since the dish will be cold.
How Should I Store Leftovers?
Store any leftovers in an airtight container in the fridge for up to 3 days. Reheat gently in the oven or microwave until warmed through.
What Can I Substitute for Gruyère Cheese?
If Gruyère isn’t available, Swiss cheese, Fontina, or sharp cheddar make great substitutes. Each will slightly change the flavor, but all melt nicely for that creamy, cheesy top.
