Cheesy Sweet Potato Gratin (Printable Format)
Layers of sweet potatoes, caramelized onions, and cheeses baked to golden perfection.
# What You Need:
→ Vegetables
01 - 2 lbs sweet potatoes, peeled and thinly sliced
02 - 2 large yellow onions, thinly sliced
03 - 2 cloves garlic, minced
→ Dairy & Cheese
04 - 2 cups shredded Gruyère cheese
05 - 1 cup shredded sharp cheddar cheese
06 - 1 1/2 cups heavy cream
07 - 1/2 cup whole milk
08 - 3 tbsp unsalted butter
→ Seasonings
09 - 1/2 tsp dried thyme
10 - 1/2 tsp ground black pepper
11 - 1/2 tsp salt (plus more to taste)
12 - 1/4 tsp ground nutmeg
→ Optional
13 - 1 tbsp gluten-free flour (or all-purpose flour) for thickening
14 - 2 tbsp chopped fresh chives for garnish
# How-To Steps:
01 - Preheat your oven to 375°F. Grease a 9x13-inch baking dish with butter or cooking spray.
02 - In a large skillet over medium heat, melt 2 tbsp butter. Add sliced onions and a pinch of salt. Cook, stirring frequently, until onions are deeply golden and caramelized, about 20-25 minutes. Add minced garlic and cook for 1 minute more. Remove from heat.
03 - In a small saucepan, heat heavy cream, whole milk, dried thyme, ground nutmeg, black pepper, and remaining 1 tbsp butter over medium-low heat until steaming (do not boil). If using flour for thickening, whisk it in until smooth and slightly thickened.
04 - Arrange half of the sweet potato slices in the prepared baking dish. Season lightly with salt. Spread half of the caramelized onions over the potatoes. Sprinkle with half of the Gruyère and cheddar cheese.
05 - Create a second layer with remaining sweet potatoes, caramelized onions, and cheese blend. Ensure even distribution of ingredients.
06 - Pour the warm cream mixture evenly over the layered ingredients, ensuring the liquid penetrates through all layers.
07 - Cover the baking dish tightly with aluminum foil and bake for 40 minutes to allow potatoes to cook through.
08 - Remove foil and continue baking uncovered for an additional 20 minutes, or until the top is golden brown and bubbly, and potatoes are fork-tender.
09 - Let the gratin rest for 10 minutes before serving to allow the layers to set. Garnish with chopped fresh chives if desired.
# Expert Suggestions:
01 -
- The sweet and savory combo hits every comfort button you didn't know you had
- It looks impressive but basically assembles itself while the oven does the heavy lifting
02 -
- Don't rush the onions because that deep caramelized flavor is what makes this dish special
- Slice the potatoes as thin and even as possible so they all finish cooking at the same time
03 -
- A mandoline makes quick work of slicing all those sweet potatoes paper thin and even
- Letting it rest for 10 minutes makes serving much cleaner and neater