Cheesy Potato Gratin with Caramelized Onions

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)

Cheesy Potato Gratin

5 from 13 votes
Serves 8 people
Prep Time 10 mins
Cook Time 1 hr 10 mins
Total Time 1 hr 20 mins

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 1/2 cups heavy cream
  • 1 cup shredded Gruyère cheese
  • 3/4 cup shredded parmesan cheese
  • 1/4 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 1/8 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 3/4 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 1/4 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.

97 Comments

  1. I see that you can make a day ahead, can you make two days ahead and still apply the par-bake method? Thanks and happy holidays!

  2. 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. 5 stars
    This was a HUGE hit at Christmas dinner. So easy to prepare (with the help of a mandoline to thinly and evenly slice potatoes). Thanks for this recipe, Gaby!

  4. Can you make this a day ahead and reheat in the oven or would it be to dry the next day? Thanks! Love all your recipes!

Leave a Reply

Your email address will not be published.

Recipe Rating