Vegetables

• 1 (2-pound) butternut squash, peeled, halved lengthwise, and seeded
• 3 tablespoons extra-virgin olive oil, divided
• 1 teaspoon kosher salt, divided
• 1/4 teaspoon black pepper, divided
• 3 (4-ounce) packages sliced mixed wild mushrooms (such as cremini, oyster, and button)
• 1 (5-ounce) package fresh baby spinach

Asiago-Garlic Mornay Sauce

• 6 tablespoons unsalted butter
• 4 garlic cloves, minced
• 1 1/2 teaspoons finely chopped fresh rosemary, plus more for garnish
• 1/3 cup all-purpose flour
• 5 cups whole milk
• 4 ounces Asiago cheese or Parmesan cheese, finely shredded (about 1 cup)
• 2 teaspoons kosher salt
• 1/4 teaspoon black pepper

Additional Ingredients

• Cooking spray
• 1 (15-ounce) container whole-milk ricotta cheese
• 1 large egg, lightly beaten
• 1 teaspoon grated lemon zest
• 1 teaspoon kosher salt
• 1 (8-ounce) package no-boil lasagna noodles
• 18 low-moisture, part-skim mozzarella cheese slices
• 2 ounces finely shredded Asiago cheese or Parmesan cheese (about 1/2 cup)
• Chopped fresh flat-leaf parsley