Butternut Squash and Mushroom Gratin

I’m resurfacing after a month of working on the book + traveling to share a cozy recipe with you just in time for the upcoming holiday season. Like many folks, my stomach has a hard time with heavy cream and the like, but I do love a good savory creamy dish, so I made this decadent layered butternut squash and mushroom gratin that has the flavor and texture of a traditional gratin, but without the buckets of cream. Instead, there’s a savory cashew garlic cream sauce that’s silky smooth and full of deep savory flavor, plus lots of grated parmesan cheese. Parmesan is an aged cheese, and a result of the aging process is that it loses most of its lactose, so it’s much gentler on the tummy. Your body and your holiday guests will thank you! (And if you’re going for a plant-based dish, you can easily swap out for a vegan parm 👍).

As for this holiday season, we’re hosting Thanksgiving at the homestead for the first time this year and I am positively vibrating with excitement about it. The whole family is spending the night, so it will be a very pleasantly full house. I’m really looking forward to staying up late with everyone after a good meal and relaxing by the fire—this house was made with the intention of hosting people and gathering them together, so it feels really good to be able to hear a cacophony of laughter and voices echo throughout the walls. (And you can bet that this squash and mushroom gratin will be on the table!) And for anyone still piecing together their holiday menus, you can take a look at some of my favorites here. Wishing my fellow stateside readers a wonderful Thanksgiving, and a beautiful end-of-autumn to all! I’m hoping to be back again next month with a festive winter recipe to share—not sure yet if it will be salty or sweet, so stay tuned 🙂

Print

Butternut Squash and Mushroom Gratin

This savory creamy side dish is full of rich umami flavor, and thanks to the parmesan and creamy garlic cashew sauce, it won't leave you or your guests with a stomach ache, either! Perfect for enjoying the cozy holiday season to the fullest.

Course Side Dish

Cuisine American

Keyword squash gratin

Prep Time 30 minutes

Cook Time 1 hour 10 minutes

Servings 6 people

Calories 289 kcal

Ingredients

• 2 pounds butternut squash peeled and cut into ⅛-inch thick rings
• 1 tablespoon plus 2 teaspoons olive oil
• 8 ounces mushrooms chopped
• 6 ounces yellow onion halved and cut into ¼-inch thick slices
• 1 ¾ teaspoons salt
• 1 cup raw cashews soaked for 4 hours or up to overnight, then drained
• 1 ⅔ cups water
• 4 garlic cloves roughly chopped
• 1 teaspoon garlic powder
• ½ teaspoon white pepper
• ½ teaspoon dried rubbed sage
• ¼ teaspoon black pepper
• 1 tablespoon fresh thyme leaves
• 3 ounces parmesan cheese or vegan parmesan grated

Instructions

1. Heat 1 tablespoon of the olive oil in a large frying pan over medium high heat. Add the onions, mushrooms, and ½ teaspoon of salt. Stir to coat in the hot oil, and reduce heat to medium. Place a lid on the pot and cook for 3 minutes to sweat out the moisture, then remove the lid and continue cooking until the onions are transparent and the most of the liquid evaporates from the pan, about 5 more minutes, stirring every couple minutes. Remove from heat and set aside.
2. In a blender or food processor, blend together the soaked cashews, water, garlic, 1 1/4 teaspoons salt, garlic powder, white pepper, and sage, until smooth and silky. Stir in the black pepper and thyme and set aside.
3. Preheat the oven to 375 degrees Fahrenheit. Grease a 9 x 13 inch baking dish and pour ¼ of the cashew mixture onto the bottom. Layer with 1/3 of the butternut squash slices in a nice even layer, then sprinkle with 1/3 of the mushroom mixture, and top with ⅓ of the grated parmesan. Repeat this layering two more times, but for the third and final layer, drizzle the mushrooms and butternut with the last ¼ of the cashew mixture and *then* sprinkle the last ⅓ of the parmesan on top. Cover with parchment paper then foil, so the parchment paper acts as a barrier between the foil and the food, and bake in the oven for 40 to 45 minutes.
4. Poke with a fork to see if the butternut is tender, then uncover and bake until the top becomes golden and bubbly, about 15 to 17 minutes more.

Nutrition Facts

Butternut Squash and Mushroom Gratin

Amount Per Serving

Calories 289 Calories from Fat 144

% Daily Value*

Fat 16g25%

Saturated Fat 4g25%

Polyunsaturated Fat 2g

Monounsaturated Fat 8g

Cholesterol 10mg3%

Sodium 921mg40%

Potassium 871mg25%

Carbohydrates 30g10%

Fiber 5g21%

Sugar 7g8%

Protein 12g24%

Vitamin A 16240IU325%

Vitamin C 37mg45%

Calcium 268mg27%

Iron 3mg17%

* Percent Daily Values are based on a 2000 calorie diet.