2 cup fresh basil, loosely packed, chopped, plus more for garnish
1/2 tsp nutmeg, freshly grated
3 tbsp olive oil
1/2 cup all-purpose flour
3 cup milk, divided
1 1/4 tsp salt
1/2 tsp ground black pepper
2 pkg 12-oz frozen cooked winter squash, thawed
2 tomatoes, diced for garnish, optional
1. Preheat the over to 400F. Cook noodles according to package directions, omitting salt and oil; drain and set aside. Meanwhile combine cheeses in a small bowl; set aside.
2. For sauce, heat oil in large saucepan over medium heat 1 minute. Add flour; whisk until completely incorporated. Gradually add 1 cup of the milk, whisking constantly until smooth. Add remaining milk, nutmeg, salt, and black pepper, whisking constantly. Bring mixture to a simmer. Reduce heat to medium-low; cook 3-4 minutes or until thickened, whisking frequently. Add squash and basil; bring to a simmer. Remove pan from heat.
3. To assemble lasagna, spread 1 cup of the sauce over bottom of 9×13 baking dish. Top with three of the lasagna noodles. Spread 1 1/4 cups of the sauce over noodles; top with half of the zucchini and about 1/2 cup of the cheese mixture. Repeat layers one time, starting with noodles. Top with remaining noodles, sauce, and cheese mixture. Cover pan with aluminum foil; back 25 minutes. Carefully remove foil. Continue to bake lasagna, uncovered, 15-17 minutes or until cheese begins to brown and center is hot. Remove pan from oven to cooling rack. Let stand, uncovered, 20 minutes. Top with additional basil and diced tomato, if desired.