2 2-lb butternut squash,peeled, halved,seeded,cut crosswise into 1/4 “-thick slices
3 tbsp. olive oil plus more
Kosher salt,freshly ground pepper
2 lb broccoli rabe,tough stems removed
Crushed red pepper flakes
1 lb fresh mozzarella,corsely grated
1 lb whole milk ricotta
1 cup finely grated Parmesan
1 tbsp finely grated lemon zest
1 tsp minced fresh sage
1 tsp minced fresh rosemary
BECHAMEL AND ASSEMBLY
1/4 cup (1/2 stick) unsalted butter
1/4 cup unbleached all-purpose flour
5 cups (or more) freshly grated nutmeg
1 bay leaf
Kosher salt , freshly ground pepper
1 lb. lasagne noodles
3/4 cup finely grated Parmesan
FILLING – Preheat oven to 400°. Place squash and 3 tbsp oil in a large bowl; season with salt and pepper and toss to evenly coat squash. Transfer to a rimmed baking sheets, spreading out in a single layer, overlapping slightly. Roast until tender but not mushy, about 15 minutes. Let cool.
Quickly blanch broccoli rabe in a large pot of boiling salted water just until it wilts, 1-2 minutes. Drain; briefly cool under running water. Squeeze out excess water; coarsely chop nd transfer to a large bowl. Season with salt, pepper , and red pepper flakes; drizzle with oil and toss to coat.
Mix mozzarella and next 5 ingredients in a large bowl; season with salt and pepper.
BECHAMEL AND ASSEMBLY-Melt butter in a large heavy saucepan over medium heat. Add flour; stir until slightly thickened (do not allow mixture to turn brown), 2-3 minutes. Increase heat slightly; slowly whisk in 5 cups hal and half, 1/2 cupful at a time, allowing bechamel to thicken betwenn additions (adding half and half gradually will help to prevent lumps from forming). Add 1/8 tsp nutmeg and bay leaf.
Reduce heat to low and cook, thinning with more half and half if too thick, until sauce is milk shake consistency. About 10 minutes longer. Season to taste with salt and pepper.
Cook Lasagne noodles in a pot with of well salted boiling water until quite al dente 8-9 minutes.
Ladle about 1/4 cup bechamel into a 13x9x2 baking dish; spread evenly over bottom. Line dish with a single layer of noodles, cutting as needed to fit. Layer 1/3 os squash over. Scatter 1/3 of broccoli rabe over.
Dollop 1/3 of ricotta mixture randomly over greens. Drizzle 1/2 cup bechamel evenly over ricotta mixture. Repeat Process 2 more times for a total of 3 layers, Finishing with a layer of noodles. Spread remaining bechamel over; top with Parmesan .
Preheat oven to 375°. Bake lasagne uncovered until bubbly and starting to brown, about 45 minutes. Turn over to broil. Cook until browned and golden, 4-6 minutes. Let rest for 20-30 minutes before serving