Sweet Potatoes au Gratin with Gruyere, Parmesan, and Pecan Topping Recipe

Introduction

Sweet Potatoes au Gratin is a comforting and elegant side dish, perfect for cozy dinners or holiday meals. Layers of thinly sliced sweet potatoes are baked in a rich, cheesy cream sauce, topped with toasted pecans for a delightful crunch.

Ingredients

• 4 sweet potatoes (around 1400g)
• 1 tbsp butter
• 1 shallot
• 1 clove garlic
• 3 sprigs fresh thyme
• 350 ml heavy cream
• 150 g grated Gruyere
• 20 g grated Parmesan
• 1 tsp nutmeg
• Salt
• Black pepper
• 20 g roughly chopped pecans

Instructions

1. Step 1: Wash and peel the sweet potatoes thoroughly.
2. Step 2: Preheat your oven to 425°F (220°C).
3. Step 3: Using a mandoline set to about 4 millimeters, slice the sweet potatoes thinly.
4. Step 4: Arrange the sweet potato slices in a spiral pattern in a cast-iron pan or any oven-safe dish. Place smaller slices at the bottom for an even appearance.
5. Step 5: Finely dice the shallot and garlic. Remove the thyme leaves from their stems. Sauté the shallot, garlic, and thyme leaves in butter over medium heat until fragrant.
6. Step 6: Add the heavy cream, half of the Gruyere cheese, and all the Parmesan to the pan. Stir until the cheese melts.
7. Step 7: Season the sauce with nutmeg, salt, and black pepper to taste. Let it simmer until the sauce thickens slightly.
8. Step 8: Pour the sauce evenly over the arranged sweet potatoes. Bake for about 45 minutes, until the potatoes are tender and the top is golden brown.
9. Step 9: About 5 minutes before it’s done, sprinkle the chopped pecans on top to toast them.
10. Step 10: Optionally, garnish with a fresh thyme sprig before serving. Enjoy your Sweet Potatoes au Gratin!

Tips & Variations

• Use a sharp mandoline or a knife to slice the sweet potatoes evenly for uniform cooking.
• Replace pecans with walnuts or omit nuts for a nut-free version.
• Add a pinch of cayenne pepper for a subtle spicy twist.
• Gruyere can be substituted with fontina or mozzarella for a different cheese flavor.

Storage

Store leftovers covered in the refrigerator for up to 3 days. Reheat gently in the oven at 350°F (175°C) until warmed through to maintain the creamy texture. Avoid microwaving to preserve the dish’s tenderness and flavor.

How to Serve

Serve this delicious recipe with your favorite sides.

FAQs

Can I prepare Sweet Potatoes au Gratin in advance?

Yes, you can assemble the dish a day ahead and refrigerate it covered. Bake it fresh before serving to maintain the best texture and flavor.

What can I use if I don’t have fresh thyme?

Dried thyme can be used as a substitute, but reduce the amount since dried herbs are more concentrated. Alternatively, rosemary or sage pairs well with sweet potatoes.

Sweet Potatoes au Gratin with Gruyere, Parmesan, and Pecan Topping Recipe

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★★★★★

4.5 from 131 reviews

Sweet Potatoes au Gratin is a rich and creamy baked dish featuring thinly sliced sweet potatoes layered in a savory cheese sauce made from Gruyere, Parmesan, butter, and heavy cream, flavored with garlic, shallots, thyme, and nutmeg, topped with toasted pecans for a delightful crunch.

• Author: Nora
• Prep Time: 15 minutes
• Cook Time: 50 minutes
• Total Time: 65 minutes
• Yield: 6 servings 1x
• Category: Side Dish
• Method: Baking
• Cuisine: French-inspired

Ingredients

Scale 1x2x3x

Vegetables

• 4 sweet potatoes (around 1400g)
• 1 shallot
• 1 clove garlic
• 3 sprigs fresh thyme

Dairy

• 1 tbsp butter
• 350 ml heavy cream
• 150 g grated Gruyere cheese
• 20 g grated Parmesan cheese

Spices & Nuts

• 1 tsp nutmeg
• salt (to taste)
• black pepper (to taste)
• 20 g roughly chopped pecans

Instructions

1. Prepare the sweet potatoes: Wash and peel the sweet potatoes thoroughly to remove any dirt and skin.
2. Preheat the oven: Set your oven to 425°F (220°C) to get it ready for baking.
3. Slice the sweet potatoes: Using a mandoline set to approximately 4 millimeters, carefully cut the sweet potatoes into thin, even slices.
4. Arrange the slices: In a cast-iron pan or any oven-safe dish, arrange the sliced sweet potatoes in a spiral pattern. Use smaller slices at the bottom so the arrangement looks uniform and even.
5. Prepare the sauce base: Finely dice the shallot and garlic, then strip the thyme leaves from their stems. Heat butter in a pan and sauté the shallot, garlic, and thyme leaves for a few minutes until fragrant.
6. Make the cheese sauce: Add heavy cream, half of the grated Gruyere, and all the Parmesan cheese to the pan. Stir continuously until the cheese melts smoothly into the cream. Season the sauce with nutmeg, salt, and black pepper to taste, and let it simmer for a couple more minutes until it begins to thicken.
7. Combine and bake: Pour the warm cheese sauce evenly over the arranged sweet potatoes in the dish. Place in the preheated oven and bake for about 45 minutes until the sweet potatoes are tender and the top is golden brown.
8. Add pecans to toast: Approximately 5 minutes before baking is complete, sprinkle the roughly chopped pecans on top to toast them lightly.
9. Garnish and serve: Optionally garnish with a fresh sprig of thyme. Serve the gratin warm and enjoy this comforting dish!

Notes

• Using a mandoline ensures the sweet potato slices are evenly thin, helping them cook uniformly.
• Gruyere cheese offers a nutty, creamy flavor, but you can substitute with Swiss cheese if unavailable.
• Be sure to watch the pecans closely when toasting towards the end to prevent burning.
• This dish pairs well as a side for roasted meats or vegetarian mains.
• Leftovers can be refrigerated and gently reheated in the oven to preserve texture.

Keywords: Sweet Potatoes au Gratin, Sweet Potato Gratin, Cheese Gratin, Baked Sweet Potatoes, Gruyere Cheese Dish, Comfort Food, Side Dish, Oven-Baked Sweet Potatoes