Winter Squash, Root Vegetable and Forest Mushroom Lasagna

Winter Squash, Root Vegetable and Forest Mushroom Lasagna
winter squash, root vegetable and forest mushroom lasagna photo by josh monken

To save time, Miller recommended preparing the precooked vegetables a day ahead.


2 large butternut squash
2 spaghetti squash
Olive oil*
Kosher salt and cracked black pepper
8 oz. portabella mushrooms, stems removed
8 oz. oyster mushrooms
3 acorn squash, peeled and seeded
6 parsnips, peeled
1 large celery root, peeled
1 medium rutabaga, peeled
1 lb. fresh spinach, blanched
1 lb. grated almond milk mozzarella, divided (available at Whole Foods Market)
Roasted chestnut sauce (recipe follows)

Roasted Chestnut Sauce
1 lb. chestnuts

2 ribs celery

1 large shallot, peeled

1½ quarts apple juice

½ lemon, juiced

*Miller doesn’t use oil in Harvest’s version, but he said home cooks might find it easier to use a little.


• Preheat the oven to 350 degrees.

• Cut 1 butternut squash and both spaghetti squashes in half lengthwise, using a spoon to remove the seeds. Lightly coat with olive oil and roast in the oven for about an hour (squash is done when soft to the touch). Keep the oven at 350 for later use.

• Using a fork, remove the spaghetti squashes’ flesh and chill it. Remove the butternut’s flesh with a spoon and season it a bit with salt and pepper before puréeing it in a food processor, then chill it.

• While the squash chills, prepare the mushrooms. Season and grill the portabellas until softened. Cut into thin slices and set aside. Season the oyster mushrooms with olive oil, salt and pepper, then roast them in the oven for about 8 minutes. When the oyster mushrooms are done, allow them to chill. Keep the oven at 350.

• Lightly oil a 13-by-9-inch baking dish. Use a mandoline to thinly slice the second butternut squash, acorn squash, parsnips, celery root and rutabaga. The slices should be about 1/8-inch thick.

• Begin layering the pan with your ingredients, including the blanched spinach and grated cheese, but reserve ½ cup of cheese for the top. There is no set order for the layers, though the raw butternut squash is firmest and should form the base. Use the butternut squash purée as your “sauce” and season each layer with salt and pepper as you build the lasagna.

• When you’re finished layering, cover the lasagna with aluminum foil and bake it for 1 hour.

• Remove the foil, sprinkle on the reserved mozzarella, and bake the lasagna, uncovered, for an additional 15 minutes. When it’s ready, remove and let sit for 5 to 10 minutes. Then slice and serve on roasted chestnut sauce.

For the Roasted Chestnut Sauce
• Preheat the oven to 350 degrees. Score the chestnuts and blanch them in boiling, salted water for 10 minutes. Transfer the chestnuts to a roasting pan and roast them in the oven for 15 minutes, rotating the pan after 8 minutes to ensure even roasting.

• Remove the chestnuts and peel them while they’re still warm. Chop the chestnuts, celery and shallots and place them in a saucepan, along with the apple and lemon juices. Simmer the mixture for 30 minutes.

• Working in small batches (never fill the blender more than halfway), purée the mixture until smooth.

• Next, push the purée through a fine mesh strainer. Return the purée to the saucepan and season with salt and pepper. Keep the sauce warm until the lasagna is ready. If it becomes thick, simply thin it with a little water.

• To plate, spoon the sauce onto the plate and place the lasagna on top.