Sweet Potato Gratin

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A Sweet Potato Gratin layered with Gouda, Thyme and Parmesan cheese! It's the perfect fall/winter side dish.

A grey dutch oven with sweet potato gratin, with a small grey ceramic plate and a spoon.

Why I Love This Recipe

While I have a au gratin potatoes recipe out there, we're having a mega sweet potato moment in our house! Poppy is obsessed with them. Thomas is obsessed with them. I am obsessed with them. The amount we buy on a weekly basis is truly wild. They are one of the most versatile vegetables to cook with. I've made them into countless recipes here on WGC and today we're turning them into a Sweet Potato Gratin!

If you know me, you know that sweet potatoes with marshmallows are a hard pass for me. But I LOVE having sweet potatoes in some form on the Thanksgiving table. This year, they are coming in the form of this gratin!

A grey dutch oven with sweet potato gratin, with a small grey ceramic plate with some sweet potato gratin and a spoon.

Layers of thinly sliced sweet potatoes mixed with 2 kinds of cheese, some heavy cream and seasonings makes this one of the easiest dishes to make!

Ingredients & Substitutions

A mise-en-place of all the ingredients to make sweet potato gratin.
  • Sweet Potatoes any variety would be delish to be honest, but I prefer the orange variety. Peel the skin and you're in business. I like to slice these with a mandolin to make it quick and uniform.
  • Heavy cream
  • Milk this is the liquid that will help the potatoes cook
  • Salt
  • Black Pepper
  • Thyme we need all of these to season these to perfection
  • Gouda if you want aged gouda, be my guest.... but you need gouda to make this the ultimate sweet potato gratin!
  • Parmesan to add a bit of saltiness

*For a full list of ingredients and instructions please see recipe card below.

How to Make Sweet Potato Gratin

A small glass mixing bowl with a mix of milk and cream.

Step 1: Preheat the oven to 400 degrees and lightly grease a cast iron skillet. Mix together the cream and milk and set aside.

A blue dutch oven with a few layers of sweet potato slices, shredded cheese and cream mixture to make sweet potato gratin.

Step 2: In the skillet, arrange the potatoes in an even layer. Drizzle with a few tablespoons of the cream mixture and season with salt, pepper, thyme and dust with some of the cheeses.

A blue dutch oven with layered sweet potatoes and cheese ready to be baked into a sweet potato gratin.

Step 3: Repeat with the remaining potatoes and cream, seasoning with salt and pepper, to form 6-8 layers. Press down on the layers to totally submerge the sweet potatoes in the cream mixture and top with additional cheese if needed.

A blue dutch oven with a freshly baked sweet potato gratin.

Step 4: Cover and bake for 30 minutes. Remove the cover and continue baking until the cream has been absorbed, the potatoes are cooked through, and the top is browned, 30 to 45 minutes. Remove from the oven and let rest for 15 minutes before serving.

How to Store Sweet Potato Gratin

You can store leftovers in the fridge for about 4 days. Make sure to warm it through in the oven when its time to eat.

How to Freeze Sweet Potato Gratin

While you can freeze these for about a month, both sweet potatoes and the cream-based sauce may lose some of their texture and flavor. To freeze, use an airtight container to avoid squishing, but you can also use freeze bags carefully. Thaw overnight in fridge and heat it in the oven till its warmed through.

Tips & Tricks

I highly recommend a mandolin. It's very tough (and requires a super sharp knife!) to cut even slices by hand.

A close up shot of sweet potato gratin garnished with thyme.

FAQs

How thin should the sweet potatoes be cut for sweet potato gratin?

Cut your sweet potatoes wafer thin, about ⅛ inch, preferably with a mandolin, to make your sweet potato gratin.

Can I store my thinly sliced sweet potatoes in water while I am prepping?

I recommend not storing potatoes or sweet potatoes in water, as is done typically. This is because the potatoes can get too moist and also lose starch, both of which are not recommended for a gratin.

Similar Recipes

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!

Gouda Sweet Potato Gratin from www.whatsgabycooking.com (@whatsgabycookin)

Sweet Potato Gratin

Author: Gaby Dalkin
5 from 13 votes
A Sweet Potato Gratin layered with Gouda, Thyme and Parmesan cheese! It’s the perfect fall/winter side dish.
Prep Time 15 minutes
Cook Time 1 hour
Resting Time 15 minutes
Total Time 1 hour 30 minutes
Course Side Dish
Cuisine American
Servings 6 people

Ingredients
  

  • 3 sweet potatoes peeled and sliced ⅛ inch thick on a mandoline
  • Kosher salt and freshly ground pepper
  • 1 teaspoon fresh thyme roughly chopped
  • ½ cup parmesan cheese shredded
  • 1 ½ cups shredded Gouda (I love the Roth Gouda wedges shredded
  • ¾ cup milk
  • ¾ cup heavy cream

Instructions
 

  • Preheat the oven to 400 degrees and lightly grease a cast iron skillet.
  • Mix together the cream and milk and set aside.
  • In the skillet, arrange the potatoes in an even layer. Drizzle with a few tablespoons of the cream mixture and season with salt, pepper, thyme and dust with some of the cheeses. Repeat with the remaining potatoes and cream, seasoning with salt and pepper, to form 6-8 layers. Press down on the layers to totally submerge the sweet potatoes in the cream mixture and top with additional cheese if needed.
  • Cover and bake for 30 minutes. Remove the cover and continue baking until the cream has been absorbed, the potatoes are cooked through, and the top is browned, 30 to 45 minutes. Remove from the oven and let rest for 15 minutes before serving.

Notes

If you want to prep these ahead of time, go ahead and par bake these after assembling. That means baking for 30 minutes, then you can remove and let cool to room temp on the counter. Then cover and refrigerate overnight. Continue to bake the following day when you are ready to serve for the additional time and make sure they are warmed through.

Nutrition Information

Calories: 460kcal | Carbohydrates: 27g | Protein: 21g | Fat: 30g | Saturated Fat: 19g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 8g | Cholesterol: 110mg | Sodium: 700mg | Potassium: 536mg | Fiber: 3g | Sugar: 8g | Vitamin A: 16932IU | Vitamin C: 3mg | Calcium: 605mg | Iron: 1mg
Tried this Recipe? Tag me Today!Mention @WhatsGabyCookin or tag #whatsgabycooking!

Photo by Matt Armendariz / Food Styling by Adam Pearson / Recipe by What’s Gaby Cooking

31 Comments

  1. Do you think it would lose flavor/texture/quality if I cooked halfway the night before & finish cooking it uncovered the day you’re serving?

  2. Can't wait to make this! Is there a different cheese you recommend using for people that don't like gouda?!

    1. sure do - gruyere would be amazing, a white cheddar would be great, fontina would be stellar!

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