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. 5 stars
    Yum!!!! I used Havarti and mascarpone rather than gruyere and crème fraiche as that's what I had on hand (apparently my fridge was feelin' fancy). It turned out great! I will put foil on for half of the bake next time as it did get a little dark, but it wasn't burnt. The taste was amazing. The family now refers to this recipe as the "gourmet cheesy potatoes"! Now I'm wondering if this could be used with pasta rather than potatoes for a mac and cheese situation? Fingers crossed for the #WGCChallenge! Thank you for sharing!

  2. This menu came just in time! I will be short oven space, how do you feel about making these potatoes in a crock pot?

    1. 5 stars
      I made this for Christmas dinner as an accompaniment to beef tenderloin with red wine sauce. I may have received the most compliments ever from my husband and we’ve been married 36 years! Thanks for a wonderful recipe.

  3. I’m feeling frustrated & perplexed, Gaby. I made this twice this week - once for elderly family under quarantine yesterday and once for my family today - both dishes were extremely brown by 30minutes and totally scorched by 1 hour. I followed your directions to a T both times, and they were baked in both an electric and a gas oven - is 400* correct? I was so looking forward to this dish and got really nice gruyere. What happened?

    1. 400 is correct! but some ovens run hot - so if that happens again and the potatoes aren't cooked through, you could cover it with foil to avoid it from browning on top but still allowing the potatoes to cook through

  4. Going to make this for Christmas! One question - I’m wondering if tossing the sliced potatoes in the cream & cheese mixture before layering them in the pan would be a good move or an unnecessary step? Any thoughts would be appreciated!!!

  5. Hi!
    YUM! Do you have a recipe for Prime Rib? I have a 10.5 LB boneless rib roast. I have not clue to how to cook it. I am going to do the potatoes and Brussels salad for the sides.

  6. 5 stars
    Just made this gratin today. It was fabulous. My husband and I ate half the dish. Will be making this for my family in Arizona when we go out there after Christmas. I couldn't get Creme Fraiche so I had to use sour cream and it was still wonderful.

  7. Hi - I've never used creme fraiche in my cooking before. Is this something you buy at the store or you make ahead of time? Do you have a recipe for this? I've seen a few different versions online. Thank you!

  8. I will need to double this for 12 people. Can I do both recipes in one pan(layering all potatoes on bottom and pour all cheese on top?)
    Oven real estate is prime on Christmas
    Help!

  9. I see in an older comment you recommend partially baking if making ahead of time. For how long would you do this? Wanting to make the day before.

  10. Love this update on a classic!
    Would you mind sourcing the pan? I've been looking for something with short handles and love the look of the one in the photos.
    Thanks!

  11. 5 stars
    This was on our Thanksgiving menu and will be there in years to come. It was excellent. The gruyere cheese made it. I did have some clear grease floating on the top. Not sure where that came from.

5 from 22 votes (6 ratings without comment)

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