Sweet Potatoes Au Gratin Recipe

Original Post: https://www.evolvingtable.com/sweet-potatoes-au-gratin/

A metal spoon is used to scoop sweet potato au gratin from a casserole dish.

5 from 2 votes

Sweet Potatoes Au Gratin Recipe

A sweet and savory twist on a classic, this Sweet Potatoes au Gratin recipe is sure to steal center stage at your holiday or Thanksgiving table! Thin slices of sweet potatoes are coated in a creamy Gruyere cheese sauce, loaded with TONS herbs and earthy spice, and finished with a crunchy crumb topping that’s irresistible.

Prep Time30

Cook Time45

Total Time1 15

Course: Side Dish

Cuisine: American

Servings: servings

Author: Jennifer Deppa

Ingredients

3 lbs. sweet potatoes cut into ⅛” slices
2 tsp. salt divided
½ tsp. black pepper
2 Tbsp. butter salted
2 Tbsp. flour all purpose or gluten-free 1-to-1 blend
4 cloves garlic finely minced
1 ½ cups milk regular or plant-based, room temperature.
1 cup Gruyere Cheese shredded
1 cup cheddar Cheese shredded
1 tsp. each of thyme and rosemary fresh
¼ tsp. nutmeg ground

Panko Parmesan Topping:

1 Tbsp. butter melted
¼ cup Panko crumbs or regular breadcrumbs
¼ cup Parmesan Cheese

Instructions

Preheat the oven to 375 degrees.
Prepare the Potatoes: Rinse and scrub the potatoes to remove any visible dirt. Dry thoroughly using a dish towel. Carefully cut the sweet potatoes into ⅛” slices using either a mandoline or a sharp chef’s knife.
3 lbs. sweet potatoes
Lay Potatoes in Baking Dish: Spray a 13x9-inch baking dish with non-stick cooking spray. Layer half of the sliced sweet potatoes in the bottom of the dish, sprinkle with ½ teaspoon salt and ¼ teaspoon of black pepper. Top with the remaining slices and another ½ teaspoon salt and ¼ teaspoon of black pepper
2 tsp. salt, ½ tsp. black pepper
Whisk the Sauce: Add the butter to a medium-sized saucepan over medium heat. Wait for it to melt before adding in the minced garlic cloves. Saute for 30-60 seconds, or until fragrant. Reduce heat to medium-low and sprinkle in the flour. Begin whisking immediately. Once it forms a thick paste, pour in ¼ cup of the room temperature milk, whisking well. When it thickens up, whisk in another ¼ cup of the milk and continue this process until all of the milk has been used and the sauce is smooth.
2 Tbsp. butter, 2 Tbsp. flour, 4 cloves garlic, 1 ½ cups milk
Mix in Cheese and Herbs: Remove the pot from the heat and add in the Gruyere cheese, cheddar cheese, fresh herbs, nutmeg, and remaining 1 teaspoon of salt. Whisk until the cheese is completely melted.
1 cup Gruyere Cheese, 1 cup cheddar Cheese, 1 tsp. each of thyme and rosemary, ¼ tsp. nutmeg
Cover and Bake: Pour the cheese sauce over the sliced potatoes in the baking dish, spreading it out using a spatula so all of the slices are coated. Cover the dish with aluminum foil and bake in the preheated oven for 30 minutes.
Add Crumb Topping: While the potatoes are baking, toss together the crumb topping ingredients in a medium-sized bowl until well combined. Remove the foil from the dish and sprinkle the crumb topping evenly over the potatoes. Continue baking for an additional 15-20 minutes, or until the topping has browned slightly and the potatoes are fork tender.
1 Tbsp. butter, ¼ cup Panko crumbs, ¼ cup Parmesan Cheese
Serve sweet potatoes au gratin immediately with a sprinkle of finely chopped fresh rosemary and thyme.

Video

Notes

Meal Prep and Storage

How to prep ahead of time: You can slice the potatoes a couple of days before, just leave them in the fridge until you're ready. Alternatively, completely assemble the dish, but save the breadcrumb topping.
How to store: Keep leftovers in an airtight container in the refrigerator for up to 4 to 5 days.
How to freeze: While you can freeze this recipe, it's best frozen without the topping. Be sure to completely cool before wrapping tightly and freezing for up to 6 months.
How to reheat: This dish is best warmed up in the oven at 350℉. You can use the microwave, but it will be mushy.

Nutrition