Butternut Squash Lasagna with Brown Butter and Sage
Make everyday meals healthier with freshly cut, flavorful sheets of vegetables, as in this hearty vegetarian lasagna. All you need is a sheet cutter attachment for your KitchenAid stand mixer to turn butternut squash into sheets that are similar in shape to lasagna noodles.
Ingredients
- 2 butternut squashes, peeled and halved crosswise, seeded half reserved for another use
- 8 Tbs. (1 stick) (4 oz./125 g) unsalted butter
- Kosher salt and freshly ground black pepper
- 2 tsp. olive oil
- 1 lb. (500 g) spinach, tough stems removed
- 1/4 cup (1 1/2 oz./45 g) all-purpose flour
- 1 Tbs. chopped fresh sage
- 3 1/2 cups (28 fl. oz./875 ml) whole milk
- Pinch of cayenne pepper
- Pinch of grated nutmeg
- 2 1/2 cups (10 oz./310 g) grated mozzarella cheese
- 1/4 cup (1 oz./30 g) grated Parmesan cheese
For the fried sage (optional):
- 2 Tbs. olive oil
- 12 fresh sage leaves
- Kosher salt
Directions
Using a KitchenAid mixer fitted with a vegetable sheet cutter attachment, cut the butternut squash necks into thin sheets. Using a sharp knife, cut the sheets into rectangles about 7 inches (18 cm) long and 3 inches (7.5 cm) wide. Place the sheets in a large bowl.
In a small saucepan over medium-high heat, melt 4 Tbs. of the butter and cook, swirling frequently, until the butter has browned and smells nutty, about 5 minutes. Pour the butter into the bowl with the butternut squash sheets and gently toss to coat the squash. Season with salt and pepper. Set aside.
In a large pan over medium-high heat, warm the olive oil. Add the spinach, season well with salt and pepper, and sauté just until wilted, about 3 minutes. Drain well, using the back of a spoon to press out as much of the liquid as possible. Set aside.
To make the béchamel sauce, in a saucepan over medium heat, melt the remaining 4 Tbs. butter. When the butter foams, add the flour and sage and cook, whisking constantly, for 1 minute. Slowly whisk in the milk a little at a time and cook, stirring constantly, until thickened, about 5 minutes.
Whisk in the cayenne pepper and nutmeg and season with salt and pepper. Set aside.
Preheat an oven to 375°F (190°C).
To assemble the lasagna, spoon a third of the béchamel into a 9-by-13-inch (23-by-33-cm) baking dish. Cover evenly with a third of the butternut squash sheets, then spread half of the spinach evenly atop the squash, followed by two-thirds of the mozzarella. Repeat to create more layers, this time using a third of the béchamel, a third of the butternut squash sheets, the remaining half of the spinach, and the remaining third of the mozzarella. Finish with the remaining third of the béchamel and remaining third of the butternut squash sheets, and finish by sprinkling evenly with the Parmesan.
Cover with aluminum foil and bake for 20 minutes. Remove the foil and continue baking, uncovered, until the sauce is bubbling and the cheese is browned, about 20 minutes more.
Meanwhile, make the fried sage: In a small fry pan over medium-high heat, warm the olive oil until shimmering. Working in batches to avoid crowding, add the sage leaves to the pan and fry until crisp, 20 to 30 seconds. Using a slotted spoon, gently transfer the leaves to a paper towel–lined plate to drain. Sprinkle the leaves lightly with salt.
Let the lasagna cool slightly, then garnish with the sage leaves and serve. Serves 8.
Williams Sonoma Test Kitchen