Name: Cheesy Onion Potato Gratin
Prep time: 20 min
Cook time: 1 h
Total time: 1 h 30 min
Yield: 8
Ingredients: 2 lbs (900g) potatoes, thinly sliced; 1 large onion, thinly sliced; 2 cups (500ml) heavy cream; 2 cups (200g) shredded cheddar cheese; 1 cup (100g) shredded Gruyère cheese; 2 cloves garlic, minced; 1 tsp dried thyme; 1/2 tsp nutmeg (optional); Salt and pepper to taste; 1 tbsp butter (for greasing the dish); Tools:; Mandoline slicer (optional but helpful for even slices); 9x13-inch baking dish; Aluminum foil

Cheesy Onion Potato Gratin

When it comes to comfort food, nothing beats the indulgent layers of a creamy cheesy onion and potato gratin. This dish holds a special place in my household, not just because it’s rich and delicious, but because it’s the ultimate crowd-pleaser at family dinners. I first made this dish on a cold winter evening when I needed something warm and hearty to lift our spirits. It turned out to be an instant hit! My kids loved the gooey cheese and creamy layers, and my husband said it was the best thing he’d eaten in weeks.

What makes this recipe a winner for me is how versatile and straightforward it is. Whether you’re preparing a festive holiday meal or just looking for a weeknight side dish that feels a little special, this gratin fits the bill. Plus, the ingredients are so simple and pantry-friendly—no fancy cheese or tools required. Every time I bring this to the table, the golden-brown crust and heavenly aroma alone are enough to bring everyone running.

I’ve tweaked this recipe over time to make it foolproof, ensuring anyone—even a busy mom like me—can whip it up without stress. And let me tell you, there’s nothing better than seeing your family scrape their plates clean and ask for seconds. So, if you’re looking for a dish that brings warmth, comfort, and a whole lot of smiles, you’ve just found it.

Questions I Often Get Asked About This Recipe:

Can I use sweet potatoes instead of regular potatoes?
Absolutely! Sweet potatoes add a subtle sweetness that pairs beautifully with the cheese and onions. Just note that they cook a bit faster, so keep an eye on them in the oven.

What’s the best cheese to use?
I recommend a mix of sharp cheddar and Gruyère for maximum flavor. But feel free to use what you have on hand—mozzarella, Parmesan, or even Monterey Jack work great.

Can I make this ahead of time?
Yes! Prepare the dish up to the baking step, cover, and refrigerate. When ready, bake as directed, adding an extra 10-15 minutes to the cooking time.

Do I need to peel the potatoes?
It’s up to you! I usually peel them for a smoother texture, but leaving the skins on adds extra fiber and a rustic touch.

What You Need to Make Cheesy Onion Potato Gratin:

Ingredients:

2 lbs (900g) potatoes, thinly sliced

1 large onion, thinly sliced

2 cups (500ml) heavy cream

2 cups (200g) shredded cheddar cheese

1 cup (100g) shredded Gruyère cheese

2 cloves garlic, minced

1 tsp dried thyme

1/2 tsp nutmeg (optional)

Salt and pepper to taste

1 tbsp butter (for greasing the dish)

Tools:

Mandoline slicer (optional but helpful for even slices)

9×13-inch baking dish

Aluminum foil

How to Make Cheesy Onion Potato Gratin:

Preheat the oven: Set your oven to 375°F (190°C).

Prep your baking dish: Grease the dish with butter to prevent sticking.

Prepare the cream mixture: In a bowl, whisk together the heavy cream, minced garlic, thyme, nutmeg, salt, and pepper.

Layer the potatoes and onions: Start with a layer of potatoes, then add a layer of onions. Sprinkle a handful of cheddar and Gruyère cheese over the onions. Repeat until all ingredients are used, finishing with a generous layer of cheese.

Pour the cream mixture: Evenly pour the cream mixture over the layers, ensuring everything is well-coated.

Cover and bake: Cover the dish with aluminum foil and bake for 45 minutes.

Uncover and finish baking: Remove the foil and bake for an additional 15-20 minutes, or until the top is golden brown and bubbling.

Let it rest: Allow the gratin to cool for 10 minutes before serving. This helps the layers set and makes it easier to serve.

Tips for Making the Best Cheesy Onion Potato Gratin:

Slice evenly: Use a mandoline slicer to ensure your potato slices are uniform, which helps them cook evenly.

Add a crispy topping: For extra crunch, sprinkle breadcrumbs or crushed crackers on top before the final baking step.

Customize the flavor: Experiment with different herbs like rosemary or parsley, or add a pinch of smoked paprika for depth.

Make it a meal: Add cooked bacon, ham, or roasted vegetables to turn this gratin into a hearty main dish.

Latest Reviews:

⭐️⭐️⭐️⭐️⭐️“Perfect comfort food for a chilly evening! My whole family loved it.”

⭐️⭐️⭐️⭐️⭐️ “I used sweet potatoes and it was divine. Will definitely make again!”

⭐️⭐️⭐️⭐️ “Great recipe, but I think I’ll add more garlic next time.”

⭐️⭐️⭐️⭐️ “It was delicious, but a bit too rich for my taste. I might try using half-and-half instead of cream.”

⭐️⭐️⭐️⭐️⭐️ “This is now my go-to dish for family gatherings. Always a hit!”

Printable Recipe:

Before you print the recipe, could I ask you a favor? Please consider sharing this recipe on Facebook or pin to a group on Pinterest? This would really help us out. Thank you so much <3