Preheat oven to 400°. Peel pumpkin; cut in half lengthwise; discard seeds or save for toasting. Cut into 1/4-in. thick slices. Place in a single layer on two greased 15x10x1-in. baking pan. Drizzle with oil; sprinkle with 1/4 teaspoon salt nutmeg. Roast until tender, 30-35 minutes. Reduce oven temperature to 350°.
Meanwhile, cook lasagna noodles according to package directions for al dente. In a large saucepan, melt butter over medium heat. Add onion; cook and stir until tender, 6-7 minutes. Add garlic; cook 1 minute longer. Stir in flour and remaining 3/4 teaspoon salt until smooth; gradually whisk in milk and sage. Bring to a boil, stirring constantly; cook and stir until thickened, 8-10 minutes. Remove from the heat; stir in Parmesan cheese. Drain noodles.
Place 3 noodles in a greased 13×9-in. baking dish. Layer with 1/3 of the pumpkin, 1-1/3 cups sauce and 1/2 cup mozzarella cheese. Repeat layers twice. Top with remaining noodles, sauce and mozzarella cheese.
Bake, covered, 30 minutes. Uncover and bake until golden brown bubbly 30-35 minutes longer. Let stand 10-15 minutes before serving. If desired, sprinkle with red pepper flakes.
We and our partners use cookies on this site to improve our service, perform analytics, personalize advertising, measure advertising performance, and remember website preferences.Ok