The Kitchen Twins' Cauliflower Truffle Lasagna

Ingredients

• 1 medium-large cauliflower head
• ¼ cup extra-virgin olive oil
• 2 shallot bulbs, diced (about ¼ cup)
• 1 teaspoon salt
• ¼ teaspoon freshly ground black pepper
• 1 ¼ cups whole milk
• ¼ cup vegetable broth
• ¼ cup grated Parmesan cheese
• ½ teaspoon ground nutmeg
• 2 tablespoons truffle oil, plus more for serving
• ²⁄3 cup chopped fresh Italian parsley
• 1 ½ cups shredded sharp Cheddar cheese
• 1 cup shredded mozzarella
• One 9-ounce box no-boil lasagna noodles (you won’t need the whole box unless you double the recipe)