Sweet Potato Gratin

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

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. 

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

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.

Continue layering sweet potatoes and cream

After the final layer, press potatoes down firmly in pan.

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.

Add Parmesan cheese and return to oven for 15 minutes.

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

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.
• 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?

• Vegetable Peeler
• Mandoline
• Casserole Dish

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

• Cranberry Sauce
• Green Bean Almondine
• Roasted Asparagus
• Sweet Potato Rolls
• Oatmeal Rolls
• Twice Baked Sweet Potatoes

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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