Cheesy Root Vegetable Gratin is a comforting dish packed with tender slices of root veggies like potatoes, carrots, and parsnips, all baked under a bubbly, golden layer of melted cheese. It’s rich, creamy, and full of warm, earthy flavors that feel just right on chilly days.
I love making this gratin because it feels like a special treat but is actually pretty simple to put together. The mix of veggies keeps it interesting, and the cheese brings everything together in a way that makes everyone ask for seconds. My favorite cheese to use is sharp cheddar, but a mix with Gruyère works beautifully too.
Whenever I serve this, I usually pair it with a fresh green salad or some roasted chicken to balance out the richness. It’s one of those dishes that’s perfect for holiday dinners or cozy family meals, and it always brings a bit of warmth and comfort to the table. Give it a try and watch how quickly it disappears!
Key Ingredients & Substitutions
Root Vegetables: The mix of yellow potatoes, sweet potatoes, and beets gives this dish a nice balance of flavors and colors. If you can’t find beets, try using parsnips or turnips for a similar earthy taste.
Cream & Milk: Using both heavy cream and whole milk creates a rich but not too heavy sauce. For a lighter version, you can swap cream for half-and-half or full-fat coconut milk for a dairy-free option.
Cheese: Gruyère adds a nutty flavor and melts wonderfully. Sharp cheddar is a good alternative if you want more tang. Mixing cheeses can give you both great flavor and gooey texture.
Thyme: Fresh thyme adds a herbal note that brightens the richness. If you don’t have fresh, dried thyme works fine—just use about half the amount.
How Do You Get Perfectly Tender and Flavorful Root Vegetables in a Gratin?
The key is slicing the veggies evenly and ensuring they cook through without drying out.
- Slice all vegetables thin, about 1/8 inch thick, for even cooking.
- Layer them tightly in rows or overlapping circles to hold moisture.
- Pour warm cream mixture gently over the veggies so they cook evenly.
- Cover with foil to trap steam during most of the bake time, then remove foil to brown the top.
- Let the gratin rest after baking to let the cream thicken and flavors meld.
Taking these steps helps prevent sogginess and ensures a creamy, tender dish with a beautifully browned cheese crust.
Equipment You’ll Need
- Sharp chef’s knife – to slice the root vegetables evenly and thinly.
- Cutting board – provides a safe surface for slicing your veggies.
- Large baking dish (oval or rectangular) – big enough to layer the vegetables without overcrowding.
- Medium saucepan – to gently warm the cream and infuse it with garlic and thyme.
- Measuring cups/spoons – for accurate cream, milk, and seasoning amounts.
- Aluminum foil – to cover the dish while baking and keep moisture in.
- Grater – to shred cheese fresh for the best melt and flavor.
Flavor Variations & Add-Ins
- Swap beets for parsnips or turnips for a milder earthy taste and similar texture.
- Stir in cooked crumbled bacon or pancetta for a salty, smoky boost that pairs well with the creamy gratin.
- Add fresh rosemary or sage instead of thyme for a different herb note that complements root vegetables nicely.
- Top with breadcrumbs mixed with melted butter before baking uncovered to add a crunchy texture contrast.
Cheesy Root Vegetable Gratin
Ingredients You’ll Need:
Vegetables:
- 2 medium yellow potatoes, thinly sliced
- 2 medium sweet potatoes, thinly sliced
- 2 medium beets, peeled and thinly sliced
Cream Mixture:
- 2 cups heavy cream
- 1 cup whole milk
- 2 cloves garlic, minced
- 1 teaspoon fresh thyme leaves (plus extra for garnish)
- Salt and freshly ground black pepper, to taste
- Optional: pinch of nutmeg
Other:
- 1 ½ cups grated Gruyère cheese (or cheddar mix)
- 2 tablespoons unsalted butter, for greasing the dish
Time You’ll Need
Plan for about 15 minutes to prepare the vegetables and cream mixture, plus 50-55 minutes baking time. Allow an extra 10 minutes for cooling before serving, so flavors set just right.
Step-by-Step Instructions:
1. Prepare Oven and Dish:
Preheat your oven to 375°F (190°C). Generously butter a large oval or rectangular baking dish so the gratin won’t stick and has rich flavor.
2. Warm the Cream Mixture:
In a medium saucepan over medium heat, gently warm the heavy cream, milk, minced garlic, and thyme leaves. Heat it until it’s steaming but not boiling. Season with salt, pepper, and a little nutmeg if you like. Take it off the heat and set aside.
3. Arrange the Vegetables:
Layer the thinly sliced root vegetables in the baking dish. Arrange the sweet potatoes along one side, yellow potatoes in the center, and beets on the other side. This creates a pretty colorful pattern.
4. Add Cream and Cheese:
Pour the warm cream mixture evenly over the layered vegetables to cover them mostly. Next, sprinkle 1 cup of the grated cheese evenly on top.
5. Bake Covered:
Cover the dish with aluminum foil and bake for 35-40 minutes. Check if the vegetables are tender by piercing with a knife.
6. Brown the Top:
Remove the foil, sprinkle the rest of the cheese (½ cup) evenly over the top. Bake uncovered for another 15 minutes, or until the cheese is golden brown and bubbly.
7. Finish and Serve:
Once baked, garnish with fresh thyme leaves. Let the gratin cool for about 10 minutes to allow the flavors to blend and the dish to set before serving.
This colorful and cheesy root vegetable gratin makes a fantastic side or main dish, full of comforting, creamy goodness!
Can I Use Frozen or Pre-Sliced Vegetables?
It’s best to use fresh vegetables for even cooking and texture, but if you use frozen, make sure to thaw and pat them dry thoroughly to avoid excess moisture in the gratin.
Can I Make This Recipe Ahead of Time?
Absolutely! Assemble the gratin and refrigerate it covered for up to 24 hours. When ready, bake it as directed, adding a few extra minutes if baking straight from the fridge.
What’s a Good Cheese Substitute?
If you don’t have Gruyère, sharp cheddar or a blend of mozzarella and Parmesan works well. Choose cheeses that melt nicely and have a flavorful punch.
How Do I Store Leftovers?
Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat gently in the oven or microwave, adding a splash of cream if needed to keep it creamy.
