For squash filling:
2 Tbls. melted butter
1 tsp. salt
1/4 tsp. white pepper
1/8 tsp. nutmeg
2 Tbls chopped fresh sage (ideal) or 2 tsp. powdered dry sage
3 lbs. Butternut squash, peeled, seeded, and sliced ¼ inch thick
1 cup (4 oz) hazelnuts , toasted - remove skins by rubbed off with a kitchen towel and coarsely chop
For the sauce:
1 large onion, chopped
2 to 4 cloves garlic, minced
6 Tbls. unsalted butter
5 Tbls. all-purpose flour
5 cups milk or chicken stock, or a blend of both, heated with the bay leaf for 10 minutes
1 bay leaf
1 cinnamon stick
1/4 tsp. Nutmeg or to taste
1 tsp. salt or to taste
1/8 tsp. white pepper or to taste
Dash cayenne pepper
For assembling lasagna:
12 oz good quality fresh mozzarella, drained well and sliced thinly
3 oz. finely grated Parmigiano-Reggiano or Pecorino (1 cup)
12 (7- by 3 1/2-inch) sheets no-boil lasagna (1/2 lbs.)
Preheat oven to 375˚ and cover two cookie sheets with parchment paper. In a small bowl, stir the salt, pepper, nutmeg and sage to blend.
In a large bowl, toss the sliced squash with the melted butter. Sprinkle the spice mixture over squash and toss. Place the squash on the parchment-lined cookie sheets in a single layer and roast until just tender, 10- minutes. Toss with a spatula if needed. Cool.
Turn oven to 350˚F
Make sauce while squash cooks:
In a pot, heat the broth and/or milk with the bay leaf and cinnamon stick.
Heat 1 Tbls. of the butter in a 3-quart heavy saucepan over moderately low heat. Add the onion and garlic and sauté until soft but not brown. Pour into a bowl and set aside.
Heat the remaining 5 Tbls. butter in the saucepan over moderately low heat. Add the flour to make a roux whisking until smooth. Cook for 3-4 minutes, stirring without brown. Remove the bay leaf from the milk/stock and discard.
Pour the stock/milk into the roux in a slow stream whisking all the while. Bring to a boil, whisking constantly, then reduce heat and simmer. Add the bay leaf and cinnamon stick and simmer, whisking occasionally, for 5 minutes or so.
Remove the bay leaf and cinnamon and add the onion-garlic mixture and stir. Season to taste with salt, pepper, cayenne and nutmeg. Remove from heat.
Toss the cheeses together in a small bowl.
Spread 1/2 cup sauce in a buttered 13- by 9- by 2-inch glass baking dish (or other shallow 3-quart baking dish) and cover with 3 to 4 pasta sheets, leaving spaces between sheets.
Spread with ⅔ cup sauce and one third of the squash and chopped hazelnuts, then add ⅓ of the cheese.
Repeat layering 2 more times, beginning with pasta sheets and ending with cheese. Top with remaining 3 pasta sheets, remaining sauce, and remaining cheese.
Butter a piece of foil that will cover your dish. Tightly cover the lasagna with the buttered foil and bake in middle of oven 30 minutes.
Remove foil and bake until golden and bubbling, 10 to 15 minutes more. Let lasagna stand 15 to 20 minutes before serving
I have found the hazelnuts pre-skinned at Whole Foods in the bulk section
To peel the butternut squash easily, set the entire squash in your oven as it preheats for 5-10 minutes. Test with a sharp knife. After 5 minutes or so the squash will have baked just enough to make the skin soft. Cool and peel the squash with a sharp knife.
Filling and sauce can be made one day ahead and kept separately, chilled.
Place plastic wrap directly on the sauce to prevent a skin from forming. Bring to room temperature before assembling.
Adapted from Gourmet Magazine, December 2001