Photo and recipe courtesy sassyradish.com
Adapted liberally from Gourmet
Ingredients:
Squash Filling
2 large onions, chopped
3 tbsp unsalted butter
2 lb butternut squash, peeled, seeded, and cut into 1/2-inch pieces
1 tsp minced garlic
1 tsp salt
1/4 tsp black pepper
1/4 cup (maybe a few tbsp more) vegetable broth
2 tbsp chopped fresh flat-leaf parsley
4 tbsp chopped fresh sage
1 cup pistachios, toasted and coarsely chopped
Béchamel:
1 tsp minced garlic
3 tbsp unsalted butter
5 tbsp all-purpose flour
5 cups milk
1 bay leaf
1 tsp salt
1/8 tsp black pepper
For Assembling Lasagna:
1/2 lb fresh mozzarella, coarsely grated (2 cups)
1 cup finely grated Parmigiano-Reggiano (3 oz)
12 (7- by 3 1/2-inch) sheets no-boil lasagne, or regular lasagne sheets, cooked according to instructions on the package, drained and cooled (1/2 lb)
Directions:
To Make Squash Filling:
In a deep, 12-inch, heavy skillet over moderate heat, cook the onions, stirring occasionally, until golden, about 10 minutes. Add squash, garlic, salt, pepper, and broth and cook, covered, stirring occasionally, until squash is just tender, about 15 minutes. Remove from heat and stir in parsley, sage, and nuts. Bring filling to room temperature.
To Make Béchamel Sauce While Squash Cooks:
In a 3-quart heavy saucepan, cook garlic in butter over moderately low heat, stirring, for 1 minute. Whisk in flour and cook, whisking, 3 minutes—this will make your roux. Add milk in a thin, constant stream, whisking all the while. Add bay leaf and bring to a boil, whisking constantly, then reduce heat and simmer, whisking occasionally, 10 minutes. Your béchamel will thicken. Whisk in salt and white pepper, discard bay leaf, and remove from heat. (Cover surface of sauce with wax paper if not using immediately.)
To Assemble Lasagna:
Preheat oven to 425°F.
Toss cheeses together. Spread 1/2 cup sauce in a buttered 13x9x2-inch glass baking dish (or some other shallow 3-quart baking dish) which is facing you lengthwise, and cover with 3 pasta sheets going the width of the dish, leaving spaces between sheets. Spread with 2/3 cup sauce and one third of filling (not 1/3 cup, 1/3 of the ENTIRE filling), then sprinkle with a heaping 1/2 cup 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.
Tightly cover baking dish with buttered foil and bake lasagna in middle of oven 30 minutes. Remove foil and bake until golden and bubbling, 10-15 minutes more (my oven did it in 15, yours might run hotter). Let lasagna stand 15-20 minutes before serving.
In the meantime, you can fry some leftover sage leaves in some olive oil. Over low heat, warm olive oil until it simmers and gently fry sage leaves (when dropped in oil). Leaves are done when the bubbling around them subsides. I, of course, was too hungry to do this. But no reason why you can’t make ahead. I am just bad at planning.