Cheesy Root Vegetable Gratin is a delicious way to enjoy a mix of tender root veggies baked in a creamy cheese sauce. Think sweet potatoes, carrots, and parsnips layered together with lots of melty cheese on top, creating a golden, bubbly crust that’s hard to resist. It’s a comforting dish with a nice balance of soft veggies and rich, cheesy flavor.
I love making this gratin when I want something cozy but still a little special. The best part is how easily you can switch up the root vegetables depending on what you have on hand or what’s in season. I usually add a little garlic and thyme for extra flavor, and it smells so good while it’s baking! It’s one of those dishes that makes the whole house feel warm and inviting.
My favorite way to serve this gratin is alongside a simple green salad or some roasted chicken for a family dinner. It’s a great side that always gets compliments, and leftovers taste even better the next day. If you like cheesy, creamy comfort food with a veggie twist, this is definitely a recipe you’ll want to keep handy.
Key Ingredients & Substitutions
Root Vegetables: Sweet potatoes, parsnips, potatoes, and beets bring great flavor and texture. If you want, swap beets for turnips or rutabagas. Just keep all slices thin for even cooking.
Heavy Cream: This adds creaminess. For a lighter option, use half-and-half or a mix of milk and cream. Coconut milk works too, but expect a different taste.
Cheese: Gruyère offers a nice melt and nutty flavor. If you can’t find it, Parmesan or a mix of mozzarella and sharp cheddar is a good alternative. I like adding Parmesan on top for extra crispness.
Herbs and Garlic: Fresh thyme is my favorite here, but rosemary or sage work nicely. Fresh garlic gives a subtle kick; roasting it first softens the sharpness if you prefer.
How Do I Get Thin, Even Slices for Perfect Cooking?
Slicing the root vegetables thin and even is key to this gratin cooking well and looking beautiful. Here are some tips:
- Use a sharp knife or a mandoline slicer for consistent thickness, about ⅛ inch thick.
- If using a knife, take your time to cut steady, even slices to avoid uneven cooking.
- Keep the slices uniform so they cook at the same rate and fit neatly in the dish when layered.
- Arrange them slightly overlapping to help hold the shape and ensure cream seeps between layers.
With evenly sliced veggies, your gratin will cook through perfectly and have a lovely texture all the way through!
Equipment You’ll Need
- Mandoline slicer – helps slice root vegetables thin and evenly for perfect cooking.
- Large baking dish or gratin dish – roomy enough for layering veggies and cheese.
- Medium saucepan – to warm the cream, garlic, and herbs together gently.
- Cheese grater – for shredding the Gruyère or Parmesan evenly over the gratin.
- Aluminum foil – to cover the dish while baking and keep moisture in.
Flavor Variations & Add-Ins
- Add cooked crumbled bacon or pancetta for a smoky, meaty touch to the gratin.
- Swap Gruyère for sharp cheddar if you prefer a stronger, tangier cheese flavor.
- Mix in sautéed mushrooms or caramelized onions between layers for extra depth and sweetness.
- Sprinkle nutmeg or smoked paprika into the cream for a warm, unique seasoning twist.
Cheesy Root Vegetable Gratin
Ingredients You’ll Need:
- 2 medium sweet potatoes, peeled and thinly sliced
- 2 medium parsnips, peeled and thinly sliced
- 2 medium potatoes, peeled and thinly sliced
- 2 medium beets, peeled and thinly sliced
- 3 cups heavy cream
- 2 cloves garlic, minced
- 1 tablespoon fresh thyme leaves (or 1 teaspoon dried thyme)
- 1 ½ cups grated Gruyère cheese (or a mix of Gruyère and Parmesan)
- Salt and freshly ground black pepper, to taste
- Butter for greasing the baking dish
How Much Time Will You Need?
This recipe takes about 15 minutes to prepare, plus 1 hour and 5-10 minutes for baking. After baking, let it rest for 10 minutes before serving. So, set aside roughly 1 hour and 30 minutes from start to finish.
Step-by-Step Instructions:
1. Prepare Your Oven and Dish:
Preheat your oven to 375°F (190°C). Take your baking or gratin dish and butter it well to prevent sticking and help the edges crisp up nicely.
2. Make the Cream Infusion:
In a medium saucepan, pour in the heavy cream. Add the minced garlic and thyme leaves. Warm this mixture over medium heat until it’s hot but not boiling – this helps the garlic and thyme flavors infuse the cream. Then, remove it from the heat and set aside.
3. Layer the Vegetables:
Arrange your thinly sliced sweet potatoes, parsnips, potatoes, and beets in the baking dish. You can layer them in rows or sections – whatever looks nice to you! Make sure slices are slightly overlapping to help everything cook evenly.
4. Add Seasoning and Cream:
Sprinkle salt and freshly ground black pepper over the layered vegetables generously. Then, pour your warm cream mixture slowly over the top, letting it seep down between the slices.
5. Add Cheese and Bake:
Sprinkle the grated Gruyère cheese evenly over everything. Cover your dish tightly with aluminum foil. Place it in the oven and bake for about 40 minutes.
6. Finish Baking Uncovered:
Carefully remove the foil and bake uncovered for another 25-30 minutes. The top should turn golden brown and bubbly, and the vegetables should be tender when tested with a fork or knife.
7. Let It Rest and Serve:
Once baked, take the dish out and let the gratin rest for 10 minutes. This helps it set and makes it easier to serve. Enjoy warm as a delicious, cheesy, comforting side or vegetarian main dish!
Can I Use Frozen Vegetables for This Gratin?
It’s best to use fresh root vegetables for even cooking and the best texture. If you must use frozen, thaw them completely and pat dry to avoid excess moisture, but fresh veggies will give you the best results.
Can I Make This Gratin Ahead of Time?
Absolutely! Prepare and assemble the gratin, then cover and keep it in the fridge for up to 24 hours before baking. Just add an extra 5-10 minutes to the baking time if cooking straight from the fridge.
How Should I Store Leftovers?
Store leftovers in an airtight container in the fridge for up to 3 days. To reheat, warm gently in the oven at 350°F (175°C) until heated through, so the top stays crispy.
Can I Substitute Different Cheeses?
Yes! Gruyère is ideal for melt and flavor, but you can also use Parmesan, cheddar, or a mix. Just consider stronger cheeses may change the final taste.
