Caramelized Onion Potato Gratin

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Give me all the gratins please!! This Cheesy Potato Gratin is one for the record books and you need it STAT.

Cheesy Potato Gratin from www.whatsgabycooking.com (@Whatsgabycookin)


 

I mean, what's not to love about thinly sliced potatoes layered with caramelized onions, heavy cream, tons of cheese, herbs, salt and pepper? It's basically the most magical side dish on the planet. And I am NOT to be left alone with it.  Somehow this Cheesy Potato Gratin always disappears very quickly and I don't want to be held accountable.

This will be making an appearance on my holiday dinner party table this year and I am 100% confident in saying you should be doing the same. TRUST. It's the best. Potato Gratin for EVERYONE.

Cheesy Potato Gratin from www.whatsgabycooking.com (@Whatsgabycookin)

If you tried this recipe, please leave a 🌟 star rating and let me know how it goes in the 📝 comments below. Thanks for visiting today

Cheesy Potato Gratin from www.whatsgabycooking.com (@Whatsgabycookin)

Cheesy Potato Gratin

Author: Gaby Dalkin
5 from 22 votes
Give me all the gratins please!! This Cheesy Potato Gratin is one for the record books and you need it STAT.
Prep Time 10 minutes
Cook Time 1 hour 10 minutes
Total Time 1 hour 20 minutes
Course Side Dish
Cuisine French
Servings 8 people

Ingredients
  

  • 2 pounds Yukon Gold potatoes (Russet potatoes also work as do sweet potatoes or a combination of any of the above)
  • Kosher salt and freshly ground pepper
  • 1 tablespoons olive oil
  • 1 yellow onion diced
  • 1 ½ cups heavy cream
  • 1 cup shredded Gruyère cheese
  • ¾ cup shredded parmesan cheese
  • ¼ cup crème fraîche or mascarpone cheese
  • Fresh thyme for garnish

Instructions
 

  • Preheat an oven to 400°F. Grease a 9-inch baking dish with butter or non-stick cooking spray.
  • Cut the potatoes into ⅛ inch slices. Arrange the slices, slightly overlapping, on the bottom of the baking dish and season with salt and pepper.
  • In a medium skillet, heat the olive oil over medium high heat. Add the onion and sauté until starting to caramelize, about 8-10 minutes. Add the heavy cream and bring the liquid to a simmer. Simmer until slightly thickened, about 5 minutes. Stir in ¾ cup of the gruyere cheese and all of the parmesan and cook until smooth and melted. Remove the mixture from the heat, let cool slightly and stir in the crème fraîche. Season with salt and pepper.
  • Pour the cream mixture evenly on top of the potatoes and sprinkle the remaining ¼ cup of Gruyere cheese evenly on top. Bake until golden brown and bubbly and the potatoes are fork tender when pierced with a knife, about 45 minutes to 1 hour. Let the gratin rest for about 15-30 minutes before serving. Garnish with thyme and serve.

Notes

I recommend learning to use a mandolin. With the safety features and patience you can easily cut even slices without getting your fingers.

Nutrition Information

Calories: 379kcal | Carbohydrates: 23g | Protein: 12g | Fat: 27g | Saturated Fat: 16g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 8g | Cholesterol: 79mg | Sodium: 290mg | Potassium: 571mg | Fiber: 3g | Sugar: 3g | Vitamin A: 933IU | Vitamin C: 24mg | Calcium: 331mg | Iron: 1mg
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106 Comments

  1. Gaby, This is the best potato gratin and is a huge hit of the family. We have had it with beef roasts, steaks and Pork Roasts. All fabulous! I have melted butter in a cast iron pan and then laid my potatoes on it to provide a crispness. It was fabulous.

    This is our go to and I greatly appreciate you sharing! Your recipe has been shared to so many of our friends and family!

    Your cookbook is also my go-to present for white elephants gift exchanges and birthday gifts with a bottle of wine.

    Christie

  2. Hi Gaby!

    Would it work to prep this entirely and then wait 2 hours before baking it in the oven? I want to make for Christmas lunch but am not at my house and don’t want to prep it away from home. It would sit with the creme & cheese mixture for a couple of hours.

    1. Awesome! Thank you!
      We just made your 5 cheese penne for my moms birthday dinner and it was the HUGEST hit!! Loooooved it!!!!

  3. Can this be easily doubled or tripled? If so, would you double all ingredients? I do a large party every year (plan for 50 people) and am needing some new ideas this year.

  4. The two times I've tried making a gratin, the cream breaks and it's a watery mess. Does mekting the cheese in the cream help prevent this? Thanks!

    1. have you tried this recipe? Or the cream breaks in other recipes you've tried? I've never had an issue with this one

  5. Hi, so excited to try! To make in advance, would you recommend completely pre-baking, par-baking or assembling then covering and put in fridge for the next day (would the potatoes brown if not at least partially baked?)?

  6. I cannot wait to make this for a bday dinner on Friday night! I just read the recipe, and am I supposed to layer potatoes then a portion of the melted cheese/cream/onion mixture and repeat? The recipe reads like I'm to layer all of the potatoes and then pour all of the mixture on top, but I'm afraid I'm misunderstanding the steps.

    Thanks!

  7. Mmmm. I think these will be a feature on my holiday table as well. I love everything about this - even the pan you have them in!

5 from 22 votes (6 ratings without comment)

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