Butternut Squash and Sweet Potato Gratin with Walnut Crust

Indulge in the cozy flavors of fall with this Butternut Squash and Sweet Potato Gratin with Walnut Crust—a dish that combines creamy comfort with a nutty crunch. Thinly sliced butternut squash and sweet potatoes are layered with a savory blend of Parmesan cheese, garlic, and thyme, then baked in a luxurious cream sauce until tender and bubbling. Topped with a golden, toasted walnut and breadcrumb crust, this gratin is as visually stunning as it is delicious. Perfect for holiday feasts or an elegant dinner side, this recipe offers a delightful contrast of textures and a balance of earthy, nutty, and creamy flavors. With minimal prep time and a crowd-pleasing presentation, it’s a must-try dish for autumn gatherings. Keywords: butternut squash gratin, sweet potato gratin, walnut crust, holiday side dish, fall recipes.

Nutriscore Rating: 70/100

Prep Time:25 mins

Cook Time:60 mins

Total Time:85 mins

Servings: 6

Ingredients

• 1 medium (about 2 lbs) butternut squash
• 2 medium (about 1 lb) sweet potatoes
• 1.5 cups heavy cream
• 0.5 cups whole milk
• 2 cloves garlic
• 2 teaspoons fresh thyme
• 0.75 cup grated Parmesan cheese
• 0.75 cup walnuts
• 0.5 cup bread crumbs
• 2 tablespoons unsalted butter
• 1.5 teaspoons kosher salt
• 0.5 teaspoons ground black pepper
• 1 teaspoon olive oil

Directions

Step 1

Preheat your oven to 375°F (190°C). Lightly grease a 9x13-inch baking dish with olive oil or butter.

Step 2

Peel the butternut squash and sweet potatoes. Slice both into thin rounds (about 1/8-inch thick) using a sharp knife or mandoline.

Step 3

In a small saucepan, combine the heavy cream, milk, minced garlic, thyme, 1 teaspoon of kosher salt, and 1/4 teaspoon of black pepper. Warm gently over medium heat until just heated through (do not let it boil). Remove from heat and set aside.

Step 4

Layer half of the butternut squash and sweet potato slices in the prepared baking dish, overlapping slightly. Sprinkle 1/4 cup of grated Parmesan cheese over the layer. Repeat with the remaining vegetables and another 1/4 cup of Parmesan.

Step 5

Pour the warm cream mixture evenly over the layered vegetables, making sure it seeps down into all layers.

Step 6

Cover the dish tightly with aluminum foil and bake in the preheated oven for 40 minutes.

Step 7

Meanwhile, prepare the walnut crust. Place the walnuts in a food processor and pulse until coarsely chopped. Add bread crumbs, the remaining Parmesan cheese (1/4 cup), and 1/2 teaspoon of kosher salt. Pulse until combined.

Step 8

Melt the butter in a small skillet over medium heat. Add the walnut mixture and stir until lightly toasted and fragrant, about 2-3 minutes. Remove from heat.

Step 9

After 40 minutes, remove the foil from the gratin. Evenly sprinkle the walnut crust over the top of the dish.

Step 10

Return the gratin to the oven and bake uncovered for an additional 20 minutes, or until the top is golden and the vegetables are fork-tender.

Step 11

Let the dish rest for 5-10 minutes before serving. Garnish with additional thyme, if desired, and enjoy!

Nutrition Facts

Serving size	(2462.6g)

Amount per serving	% Daily Value*
Calories	3210.6

Total Fat 183.6g	0%
Saturated Fat 103.3g	0%
Polyunsaturated Fat 1.5g
Cholesterol 496.6mg	0%
Sodium 3009.5mg	0%
Total Carbohydrate 326.5g	0%
Dietary Fiber 59.2g	0%
Total Sugars 69.0g
Protein 57.8g	0%

Vitamin D 53.7IU	0%
Calcium 1582.4mg	0%
Iron 15.1mg	0%
Potassium 2915.6mg	0%

*The % Daily Value tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.

Source of Calories

Fat: 51.8%

Protein: 7.2%

Carbs: 40.9%