Easy Au Gratin Sweet Potatoes Recipe For Weeknight Dinner

This Au Gratin Sweet Potatoes recipe elevates the humble sweet potato into a decadent and irresistible dish. The combination of gooey Gruyere and sharp white cheddar melds perfectly with the natural sweetness of the potatoes, creating a luxurious side that's as fitting for a weeknight dinner as it is for a festive holiday table. With its golden, crispy top and creamy interior, this recipe is a dreamy, cheesy revelation that will have you coming back for seconds.

Au Gratin Sweet Potatoes Recipe

Ingredients

1 yellow onion, sliced
1 tablespoon olive oil
1 tablespoon unsalted butter
2 cloves garlic, minced
4 lbs sweet potatoes (about 5 potatoes), peeled and sliced thin (⅛ – 1/16 of an inch)
1½ cups heavy cream
1¾ cups grated Gruyere cheese
1 cup grated white cheddar cheese
1 tablespoon fresh thyme (or 1 teaspoon dried flakes)
⅛ teaspoon fresh grated nutmeg
1 teaspoon kosher salt
Black pepper

Instructions

Preheat your oven to 350 degrees F and spray a 9x13 baking dish with nonstick cooking spray.
In a medium skillet over medium heat, add olive oil, butter, and sliced onions. Season with a bit of salt and pepper. Sauté for about 5 minutes. Add the minced garlic and sauté for another 2-3 minutes until onions are translucent.
In a large bowl, combine the sliced sweet potatoes, heavy cream, thyme, nutmeg, kosher salt, and black pepper.
Stir in the sautéed onions, 1 cup of the Gruyere cheese, and the white cheddar cheese.
Pour the mixture into the prepared baking dish, arranging evenly and pressing down lightly. Top with the remaining ¾ cup of Gruyere cheese.
Bake for 1 hour and 15 minutes until bubbly and golden brown on top.
Allow to rest for about 10 minutes before serving.

Sweet Potato Varieties Showcase

Types of Sweet Potatoes: Utilize orange, purple, and white sweet potatoes. Each type offers a unique flavor and visual impact:

Orange Sweet Potatoes are the classic choice with a sweet, creamy texture.
Purple Sweet Potatos have a denser, earthier flavor with antioxidant benefits, resulting in a striking visual layer.
White Sweet Potatoes offer a crisper texture and a slightly less sweet flavor than their orange counterparts.

Layering Tips: Create alternating layers or a color gradient, starting with white at the bottom, followed by orange, and topping with purple. This not only makes the dish pop visually but provides an instant talking point.

Cooking Considerations: Since each variety may cook slightly differently, slice them to an even thickness to ensure uniform cooking. Consider pre-roasting each type separately for a short time to ensure they all reach the perfect tenderness.

Personalized Spice Mix

Basic Spice Mix Blueprint: Start with salt and pepper, then choose from a variety of spices like paprika, garlic powder, or onion powder as a base.
Adding Herbs: Introduce dried or fresh herbs such as rosemary, sage, or thyme. Fresh herbs can be added directly to the layers, while dried ones can be mixed in with the spices.
Experimentation: Invite creativity—suggest adding a pinch of cinnamon or nutmeg for a hint of warmth, or cayenne pepper for a kick.
Use Instructions: Sprinkle the spice mix between each layer of sweet potatoes and on top before adding the cheese, ensuring the flavor permeates throughout.

Sweet to Spicy Spectrum

Adjusting the recipe from sweet to spicy allows the dish to cater to a broader range of palates and makes each cooking experience unique:

Sweet Adaptations: For a sweeter version, consider adding a drizzle of maple syrup between layers or a sprinkle of brown sugar which caramelizes beautifully under the cheese.
Savory Enhancements: Incorporate fried onions or shallots between the layers for added sweetness and texture without overpowering the dish.
Spicy Versions: For those who like it hot, adding chopped jalapeños between layers, or a dash of chili flakes can really spice things up.
Balancing Flavors: To ensure the spiciness doesn’t overpower, balance it with creamy elements like extra cheese or a dollop of sour cream on the side.

Notes

For best results, use a mandolin slicer for your potatoes to ensure an even, thin slice.
This recipe can be equally delicious with russet or red potatoes, or a combination of root vegetables like carrots and parsnips.
It can be made ahead of time and reheated in a preheated 350 degree F oven for 20-30 minutes or until warmed through and bubbly again.

This dish is perfect for a holiday meal or any occasion where you're looking to impress! Enjoy the creamy, cheesy deliciousness!