Cheesy Root Vegetable Gratin That’ll Warm Up Your Table

Gratin Tales: Why I Keep Coming Back to This Dish

So, there’s this particular memory I can’t seem to shake—my first ever attempt at making a gratin. I was home on a blustery Sunday, windows fogged up; the type of day that’s practically crying out for oven heat and something, anything, smothered in cheese. My granddad used to call anything with golden, bubbly cheese on top "bliss with a crust." And honestly? He wasn’t wrong, though he also put ketchup on everything, so take that as you will. This Cheesy Root Vegetable Gratin is now one of my go-tos, especially when I need something comforting but still feel like I’m, you know, also eating a few vegetables. Maybe not health food, but it counts.

Why You’ll Love This Gratin (Or, Why I Do Anyway)

I make this when the produce drawer looks a little sad, and I need to clear out those stray potatoes (or parsnips, or the odd carrot that’s still hanging on). My family goes absolutely bonkers for it because, let’s be honest, cheese has a way of winning everyone over. Even my cheese-averse cousin gets second helpings, though she claims “it’s just for the crispy top.” Sure, whatever floats your boat, Meg. Oh, and the best bit? There’s zero stress if you mess up the layers. As long as you don’t forget the salt like I once did (yikes), it’s always tasty.

Here’s What You’ll Need (Substitutions & All)

• 3 medium potatoes (I’ve used sweet potatoes in a pinch—bit different, but lovely!)
• 2 large carrots, peeled and sliced
• 1 small swede or rutabaga (grandma swore by Swede but honestly, turnip is fine)
• 1 parsnip (sometimes I skip this if the store’s out—it’s not a dealbreaker)
• 1 onion, thinly sliced
• 2 cloves garlic, minced
• 200g (about 2 cups) grated cheddar cheese (I’ll sometimes sneak in gruyere or even a bit of parmesan if feeling fancy or if there’s leftovers in the fridge)
• 300ml (1 ¼ cups) single cream or half-and-half (whole milk works just fine too—trust me)
• A handful of fresh thyme leaves or 1 teaspoon dried (rosemary works, but go easy—one rogue branch ruined it for me once)
• Salt & pepper (generously; stinginess leads to blandness—learnt that the hard way)
• Butter for greasing (or just a bit of oil; no need to get precious)

Let’s Put This Together (Don’t Stress!)

1. Preheat your oven to 190°C (375°F). If you forget, like I did last week, just pretend the ‘resting time’ was part of the plan.
2. Grease a medium baking dish—mine’s about 8x10 inches, but honestly, I’ve used a cake tin before in a desperate moment. Works fine.
3. Prep your veggies: peel and thinly slice all the root veg. Thinner is better, but don’t break a sweat getting them all perfect. (This is where I usually sneak a little raw potato, weirdly satisfying.)
4. Mix the sliced veggies and onion in a large bowl. Add salt, pepper, thyme, and garlic. Give it all a good toss.
5. Start layering: spread half the veg mixture into the dish, top with half the cheese. Then, go in with the remaining veg. Pour over the cream (or milk). Finish with the rest of the cheese. Sprinkle any extra thyme you remembered to save.
6. Cover with foil (shiny side in, though I’m not sure if that really matters), pop into the oven. Bake for about 35 minutes. Don’t worry if there’s some bubbling or it looks a bit soupy. That magic happens soon.
7. Remove the foil and bake another 20-25 minutes, or until everything is golden and crisp on top. If it’s not crispy enough, crank up the temp for the last 5 minutes or hit the grill for a minute or two—just watch closely. I still have a dish with permanent blackened cheese marks from not paying attention once.
8. Let it sit for about 10 minutes before serving. This gives you time to round up stray family members or, uh, pour yourself something to drink.

Notes From My Many Attempts

• I used to slice veg by hand but, actually, I find it works so much better (and way faster) with a mandoline. But careful—band-aids were involved the first couple times…
• If the cream looks like it’s curdling, don’t panic. Always turns out fine once it’s all baked up.
• Season more than you think—roots soak up salt like nobody’s business.

Variations I’ve Attempted (Not All Winners!)

• Added a layer of wilted spinach under the cheese because I had some lingering—turned out pretty good, though my son, Tom, picked it out.
• Once swapped all the cheese for blue cheese. Bit pungent, but the adults liked it (the kids, not so much... "tastes like feet," apparently).
• Tried slicing everything super thick to save time. Nope. Crunch city; wouldn’t recommend.

Equipment (And Improvising If You Must)

• A baking dish (or cake tin, or even a deep roasting tray in a pinch)
• Sharp knife or mandoline—although I managed once with a peeler, but I wouldn’t do that again. My wrist hurt for days.
• Foil—if you run out, a second upturned dish works, though it’s much less convenient

Storing: Theoretical Leftovers

Covers and keeps fine for a day or two in the fridge. I think it actually gets tastier the next day; the flavors sort of get to know each other better. But, if I’m honest, in my house it doesn’t usually last long enough to test that theory properly.

The Stuff I Serve It With (& A Family Tradition)

I love this with a simple green salad, but sometimes I just cut myself a big slab and call it brunch with a fried egg on top—very not-French, but it works for me. My partner always insists we have it with sausages, no exceptions. It’s become a bit of a running joke (and honestly, he’s not wrong, the combo is excellent).

Things I Learned the Hard Way: Pro Tips

• Don’t rush the resting step! I once tried serving it straight from the oven—turned into a lava-hot mess that scalded everyone’s tastebuds. Give it the 10 minutes, trust me.
• Slicing too thick? It won’t cook through by the time the cheese is perfect, so... thin is in, even if it seems fussy at first.
• Cheese on top only is tempting, but mixing some in the middle means cheesy goodness all through. Learnt this one the tasty way.

FAQ—Questions I Get All the Time (And a Few I’ve Made Up)

• Can I skip the cream? Sure thing. Use milk or a mix of milk and stock. It’s not exactly the same, but it works. (Though, really, cream is half the fun.)
• Does this freeze? Technically, yes, but the texture can get a bit... odd? I probably wouldn’t serve it to guests after freezing. Or, if you must, reheat in the oven for best texture.
• What if I don’t love parsnips? Just leave them out or use extra potato instead—it’ll still be delicious; it’s honestly very forgiving.
• Is it gluten-free? Yep, unless you go throwing breadcrumbs on top for crunch (sometimes I do, sometimes I don’t).
• Can I prep this ahead? Oh, totally. Assemble the whole thing, cover, and stick in the fridge a day in advance. Just factor in a bit longer in the oven if it’s cold from the fridge.

On a side note—one of my friends claims adding a splash of white wine to the cream takes it up a notch. Haven’t tried it myself yet, but one of these days I might. If you do, let me know how it turns out (unless it all evaporates, in which case, we had fun trying, didn’t we?).

★★★★★ 4.90 from 12 ratings

Cheesy Root Vegetable Gratin

yield: 6 servings

prep: 25 mins

cook: 50 mins

total: 50 mins

A comforting baked casserole of layered root vegetables smothered in a creamy cheese sauce, perfect as a hearty side or vegetarian main.

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Ingredients

• 2 medium potatoes, peeled and thinly sliced
• 2 medium carrots, peeled and thinly sliced
• 1 large parsnip, peeled and thinly sliced
• 1 small sweet potato, peeled and thinly sliced
• 1 cup heavy cream
• 1 cup grated Gruyère cheese
• ½ cup grated Parmesan cheese
• 2 cloves garlic, minced
• 2 tablespoons unsalted butter
• 1 teaspoon fresh thyme leaves
• Salt and pepper to taste

Instructions

1. 1
   Preheat the oven to 375°F (190°C). Grease a medium baking dish with butter.
2. 2
   Layer the potatoes, carrots, parsnip, and sweet potato in the prepared dish, slightly overlapping the slices.
3. 3
   In a saucepan over medium heat, melt butter and sauté garlic for 1 minute. Stir in heavy cream, thyme, salt, and pepper; heat until warm but not boiling.
4. 4
   Pour half of the cream mixture over the layered vegetables. Sprinkle with half of the Gruyère and Parmesan cheeses.
5. 5
   Add remaining vegetables, pour over the rest of the cream mixture, and top with remaining cheeses.
6. 6
   Cover with foil and bake for 35 minutes. Remove foil and bake an additional 15 minutes until golden and bubbly. Let rest for 10 minutes before serving.

CLICK FOR NUTRITION INFO ↑

Approximate Information for One Serving

Serving Size: 1 serving

Calories: 320 caloriescal

Protein: 11gg

Fat: 18gg

Saturated Fat: 0g

Trans Fat: 0g

Cholesterol: 0mg

Sodium: 0mg

Potassium: 0mg

Total Carbs: 30gg

Fiber: 0g

Sugar: 0g

Net Carbs: 0g

Vitamin A: 0

Vitamin C: 0mg

Calcium: 0mg

Iron: 0mg

Nutrition Disclaimers

Number of total servings shown is approximate. Actual number of servings will depend on your preferred portion sizes.

Nutritional values shown are general guidelines and reflect information for 1 serving using the ingredients listed, not including any optional ingredients. Actual macros may vary slightly depending on specific brands and types of ingredients used.

To determine the weight of one serving, prepare the recipe as instructed. Weigh the finished recipe, then divide the weight of the finished recipe (not including the weight of the container the food is in) by the desired number of servings. Result will be the weight of one serving.

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