Sweet Potato and Yukon Gold Bake

Side DishChristmasGluten-FreeSweet Potato

Festive crispy baked sweet potatoes and yukon gold potatoes on a bed of caramelized onions. Perfect for a holiday side!

Photography Credit: Elise Bauer

Looking for a special holiday side? Here’s a festive dish that alternates the flavors and colors of vibrant sweet potatoes with buttery yukon gold potatoes, all sitting on a bed of caramelized onions.

I actually started out to make a gratin, more in the spirit of our gruyere potatoes, perhaps with a breadcrumb topping. But as I experimented with the recipe, the wonderful flavors of the sweet potatoes and potatoes seemed to get lost in the rich toppings.

Sweet Potato Yukon Gold Bake

So the toppings got chucked in favor of a more naked gratin, the un-gratin. The gratin without the gratin part. A rainbow hasselback sweet potato and potato bake.

It’s so pretty! I found a big beautiful purple sweet potato at the market that contrasts beautifully with the garnet yam and yellow yukon golds. Sweet potatoes come in many shades, so pick a variety.

Sweet Potato and Yukon Gold Bake Recipe

  • Prep time: 15 minutes
  • Cook time: 1 hour, 25 minutes
  • Yield: Serves 6 to 8

Look for sweet potatoes that are small in diameter, long, and uniform in shape.

Going vegan? Swap out the butter in step 3 with olive oil.


Caramelized Onions:

  • 2 Tbsp olive oil
  • 4 cups sliced onions (1/8 to 1/4-inch slices)
  • 1 teaspoon fresh thyme, minced
  • 1/2 teaspoon salt

Sweet Potatoes and Yukon Golds:

  • 2 pounds of sweet potatoes, mixed in color if available, peeled and sliced into 1/8-inch thick rounds
  • 2 pounds Yukon Gold potatoes, peeled, and sliced into 1/8-inch thick rounds
  • 2 Tbsp melted butter
  • 1 teaspoon of salt
  • 1/4 teaspoon black pepper
  • Sprigs of fresh thyme


1 Caramelize the onions: Heat olive oil in a large, thick-bottomed pot on medium heat. Add the sliced onions, toss to coat, lower the heat to medium low and cover. Let cook for 15 to 20 while you are slicing the sweet potatoes and yukon golds, stirring occasionally, until completely softened.

Then increase the heat to medium high and cook uncovered until golden brown. Remove from heat and stir in salt and thyme.

2 Peel and slice all of the sweet potatoes and yukon golds. Try to make them uniform in size.

Place the slices in a bowl of water while you are prepping them to prevent them for discoloring. If using purple sweet potatoes, keep the slices in a different bowl of water (the color bleeds).

Drain the slices, place them in a bowl.

3 Line baking dish with onions, sweet potato and potato slices: Place the caramelized onions in an even layer over the bottom of a 9x12 rectangular or oval casserole dish.

Arrange slices of sweet potatoes and Yukon Gold potatoes in rows on top of the caramelized onions.

Brush with melted butter, sprinkle with salt and pepper.

4 Cover with foil and bake in a 400°F oven for 45 minutes, until the potatoes are cooked through.

5 Remove foil, bake uncovered for 15 minutes more, until the edges are crispy and browned.

Sprinkle with a little more salt and pepper. Garnish with sprigs of fresh thyme. Serve immediately.

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Gruyere Scalloped Potatoes here on Simply Recipes

Sweet Potato Casserole here on Simply Recipes

Sweet Potato Roast from Deb Perelman of Smitten Kitchen

Sweet Potato Yukon Gold Bake

Showing 4 of 13 Comments / Reviews

  • Martha

    Is there a point where this can be stopped and refrigerated so it doesn’t all have to be done Thanksgiving day? Thanks.

  • Cristina

    This is gorgeous! I’ve made the sweet potato roast from Deb Perelman that you linked to and it is fantastic! I am planning on making your variation but adding her suggested creme fraiche to drizzle on top. Can’t wait! Thanks for another great inspiration. And btw, I made your potato au gratin this year and it was a huge success.

  • Alida @My Little Italian Kitchen

    So many colours and so healthy and delicious! I love this dish, well done!

  • Evie Lieb

    Gorgeous recipes from you in this morning’s email! Thank you as always for inspiration and great taste. Happy Thanksgiving to you and your family .

  • Jean

    Gorgeous with the purple potato! Un-gratin – love it! Will be trying soon.

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