Squash and Spinach Lasagna

Peel squash; cut into 1/4-inch (5 mm) thick slices. Brush both sides with oil. Place on 2 foil-lined rimmed baking sheets. Sprinkle with 1/4 tsp (1 mL) of the salt and pepper. Roast in 450 F (230 C) oven until tender adn lightly rowned, about 30 minutes. Let cool on pans.

Tomato sauce:
Meanwhile, in large nonstick skillet, fry pancetta over medium heat until fat begins to release, about 4 minutes; drain off fat. Stir in onion, celery, garlic and hot pepper flakes; cook until vegetables soften, about 3 minutes. Add tomatoes, red wine, tomato paste, oregano and sage; reduce heat to low and simmer, stirring occasionally, until thickened, about 30 minutes. Set aside.

Béchamel sauce:
In saucepan, melt butter over medium heat; stir in flour and cook, stirring, for 4 minutes. Gradually whisk in milk; cook, whisking constantly, until bubbly. Boil for 5 minutes, whisking often. Remove from heat. Whisk in Parmesan and nutmeg; blend in eggs. Set aside.

In large pot of boiling salted water, cook noodles until almost tender, 6 to 8 minutes. Drain and chill in cold water; arrange in single layer on damp tea towel.

Rinse spinach; shake off excess water. In large saucepan, cook spinach, with just the water clinging to leaves, over medium-high heat until wilted, about 5 minutes; drain in colander. Squeeze out liquid; chop spinach and season with remaining salt. Set aside.

Spread half of the tomato sauce in 13- x 9-inch (3L) glass baking dish. Top with single layer of noodles, cutting to fit if necessary. Top with half of the squash. Spread with half of the béchamel sauce; sprinkle with one-third of the mozzarella. Repeat noodle layer; cover with spinach, then remaining squash. Top with remaining béchamel sauce. Sprinkle with half of the remaining mozzarella; top with noodles. Cover with remaining tomato sauce; sprinkle with remaining mozzarella.

Cover loosely with foil. (Make-ahead: Refrigerate for up to 8 hours. Or overwarp with heavy-duty foil and freeze for up to 2 weeks; thaw in refrigerator for 48 hours. Remove outer foil; add 10 minutes to baking time.) Bake on rimmed baking sheet in 375 F (190 C) oven for 25 minutes.

Uncover and bake until bubbly and cheese is lightly browned, about 30 minutes. Let stand for 10 minutes before serving.