Recipe/ Side Dish/ Vegetable

Sweet Potato Gratin

October 21, 2019 (Last Updated: October 20, 2019)

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Delicious Sweet Potatoes that are perfectly sweet without any added sugars or sweeteners. 

Sweet Potato Gratin topped with fresh thyme on a white plate.

Growing up, we only ate sweet potatoes for holiday dinners.  They were the required side dish topped with little marshmallows. I’ve eaten a lot of different types sweet potato casseroles since then and so many are overly sweet. These sweet potatoes are sweet, but all the sweetness comes from the potatoes themselves, not any added sugar or mini marshmallows.

What is sweet potato gratin?

This gratin is sliced sweet potatoes layered with a cream mixture and baked.  The potatoes are topped with Parmesan cheese during the last few minutes of baking to make a lovely crust.

What is the difference between sweet potatoes or yams?

According to Bon Appetit magazine, most yams from the grocery store are actually orange sweet potatoes. Back in the 1930s Louisiana sweet potato farmers called their orange sweet potatoes yams to distinguish themselves from other sweet potatoes and the name stuck.  In most grocery stores you can buy sweet potatoes (white flesh) or yams (orange flesh). I’ve used both types when testing this recipe. In a taste test, they both taste the same, but I like the orange color and tend to use the yams, or orange sweet potatoes the most often. 

What ingredients do I need?

  • Sweet Potatoes
  • Heavy Cream – 30% or 36% cream (also called whipping cream)
  • Orange peel
  • Fresh thyme
  • Fresh sage
  • Salt and pepper
  • Parmesan cheese

How do I make sweet potato gratin?

Place heavy cream in a pot along with fresh thyme, fresh sage and orange peel. Bring cream to a boil and then turn off heat. Allow mixture to sit for at least 15 minutes so the flavors steep into the cream. Strain cream removing orange peel and herbs. 

A sauce pot filled with cream, orange peel, and fresh herbs.

Peel and slice sweet potatoes. Use a mandolin set at 1/8″ or cut thin slices with a knife. Sweet potatoes being cut on a mandoline.

Layer a third of the sweet potatoes in a greased casserole dish. Sprinkle with salt and pepper and cover with a third of the cream mixture.

Sweet potatoes topped with heavy cream.

Continue layering sweet potatoes and cream Sweet potatoes in a casserole dish.

After the final layer, press potatoes down firmly in pan. A casserole dish filled with orange yams.

Cover with foil and place casserole dish on a baking sheet. Place in a preheated 350 degree oven for one hour. Remove foil and bake for an additional 45 minutes until potatoes are brown and bubbly. Browned potato gratin.

Add Parmesan cheese and return to oven for 15 minutes. Potato casserole topped with parmesan cheese.

Allow casserole to rest for 10-15 minutes before serving. Baked sweet potato casserole topped with parmesan cheese.

Can I make ahead of time?

Yes, you can make this sweet potato gratin ahead of time. Bake up to one day ahead to the step of adding the Parmesan cheese. Reheat, uncovered in a 375 degree oven until bubbly, about 20 minutes. Add cheese and bake 10 more minutes. 

Tips for making sweet potato gratin

  • Only use the outer peel from the orange. Do not use the white pith, which is bitter. 
  • Use a vegetable peeler to remove the orange peel in long strips. An orange peel being removed with a vegetable peeler.
  • Use a mandoline to make uniform sweet potato slices. Always use extreme caution when using a mandoline. The blade is razor sharp. Use the safety guard to prevent injury. 
  • Bake casserole on a baking sheet. This makes easy clean up if your casserole spills over while baking.
  • Garnish with fresh thyme before serving. 

What equipment do I need to make sweet potato gratin?

Other great holiday side dishes

If you are looking for other great holiday side dishes, I’ve got you covered! Check out these great recipes

Don’t forget to PIN for later! Sweet potatoes topped with cheese on a small plate.

If you make this recipe, I’d love to hear about it! Leave a comment below and snap a picture and tag me on Instagram @beyondthechickencoop

Check out all my Side Dish Recipes.

Recipe inspired by Fine Cooking

5 from 5 votes
Baked sweet potato casserole topped with parmesan cheese.
Sweet Potato Gratin
Prep Time
20 mins
Cook Time
2 hrs
Resting Time
10 mins
Total Time
2 hrs 30 mins
 

Sweet Potato Casserole made with cream and topped with Parmesan Cheese.

Course: Side Dish, Vegetable
Cuisine: American
Keyword: Swee Potato Gratin, Sweet Potato Casserole, Sweet Potatoes
Servings: 10 people
Calories: 293 kcal
Author: Kathy
Ingredients
  • 3 pounds sweet potatoes
  • 2 cups heavy cream
  • 3 sprigs fresh thyme
  • 4 leaves fresh sage
  • 1 orange peel
  • 1/2 teaspoon salt
  • 1/2 teaspoon pepper
  • 1/4 cup Parmesan Cheese Grated
Instructions
  1. Place cream. thyme, sage and orange peel in a sauce pan. Bring to a boil and turn off heat. Allow mixture to sit for at least 15 minutes allowing flavors infuse into cream. Strain mixture and set infused cream aside.

  2. Peel and slice sweet potatoes into 1/8" slices.

  3. Spray a casserole dish (3 1/2 quart size) with non-stick cooking spray.

  4. Layer 1/3 of the sweet potato slices in the bottom of the casserole dish, overlapping slices.

  5. Sprinkle with salt and pepper.

  6. Pour 1/3 of the infused cream over potatoes.

  7. Repeat 2 times until all sweet potatoes and cream are used.

  8. After final layer, press sweet potatoes down firmly in pan.

  9. Cover with foil and place on a baking sheet. Place in a preheated 350 degree oven for one hour. Remove foil and continue baking for 45 minutes.

  10. When sweet potatoes are cooked trough and the mixture is bubbly and browned, sprinkle on Parmesan cheese. Return to oven for 15 minutes.

  11. Allow casserole to rest for 10-15 minutes before serving.

Recipe Notes
  • Only use the outer peel from the orange. Do not use the white pith, which is bitter. 
  • Use a vegetable peeler to remove the orange peel in long strips.
  • Use a mandoline to make uniform sweet potato slices
  • Bake casserole on a baking sheet. This makes easy clean up if your casserole spills over while baking.
  • Garnish with fresh thyme before serving. 

 

To make ahead of time:

  • Bake up to one day ahead to the step of adding the Parmesan cheese.
  • Reheat, uncovered in a 375 degree oven until bubbly, about 20 minutes.
  • Add cheese and bake 10 more minutes. 
Nutrition Facts
Sweet Potato Gratin
Amount Per Serving
Calories 293 Calories from Fat 162
% Daily Value*
Fat 18g28%
Saturated Fat 11g69%
Cholesterol 67mg22%
Sodium 249mg11%
Potassium 494mg14%
Carbohydrates 29g10%
Fiber 4g17%
Sugar 6g7%
Protein 4g8%
Vitamin A 20044IU401%
Vitamin C 6mg7%
Calcium 105mg11%
Iron 1mg6%
* Percent Daily Values are based on a 2000 calorie diet.

 

 

 

 

 

 

 

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6 Comments

  • Reply
    Valentina
    October 23, 2019 at 1:36 pm

    5 stars
    I’m a sweet potato fan all year long — and especially during the holiday season. This gratin is calling my name! So delicious and comforting, and adding the touch of orange flavor is brilliant. YUM! 🙂 ~Valentina

    • Reply
      Kathy
      October 25, 2019 at 5:18 am

      Thanks, Valentina!

  • Reply
    annie@ciaochowbambina
    October 21, 2019 at 8:53 am

    5 stars
    This is going on my weekend menu! I can’t wait 5 weeks before having it!! 🙂 YUM!

  • Reply
    Dawn - Girl Heart Food
    October 21, 2019 at 5:32 am

    5 stars
    Growing up we ate a lot of regular potatoes and not sweet. These days we love both in our home! Love how delicious this looks Kathy! This would be a lovely addition to our holiday table. Nice touch with the orange – YUM!

  • Reply
    David @ Spiced
    October 21, 2019 at 5:21 am

    5 stars
    What a fun twist with the orange peel in there! Those sweet potato casseroles covered in marshmallows seem to be a ubiquitous holiday side dish. Confession time – I’ve never liked those! However, I do like sweet potatoes, and I’m thinking these savory gratin is calling my name big time right now!

  • Reply
    Mary Ann | The Beach House Kitchen
    October 21, 2019 at 5:05 am

    5 stars
    Now this would be PERFECT for the Thanksgiving table Kathy! Sweet potatoes are a favorite of mine. More so than regular potatoes. I love the added orange peel for flavor.

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