Spinach Lasagna With Mushroom Ragu

Name: Spinach Lasagna With Mushroom Ragu
Ingredients: 12 ounces dried lasagna noodles; 1 ounce dried porcini mushrooms; 2 tablespoons extra-virgin olive oil; 1 medium onion, chopped; 1 large carrot, finely chopped; 1 stalk celery, finely chopped; 4 cloves garlic, chopped; 2 tablespoons tomato paste; 2 portobello mushroom caps, chopped; 1 1/2 pounds shiitake mushrooms, stems removed, chopped; Kosher salt and freshly ground pepper; 2 28-ounce cans whole San Marzano tomatoes, crushed by hand; 3 bay leaves; 1/4 cup chopped fresh parsley; 3 ounces parmesan cheese, grated; 1 1/2 pounds part-skim mozzarella cheese, shredded; 8 ounces asiago cheese, shredded; 2 pounds ricotta cheese; 2 large eggs, lightly beaten; 1 pound frozen chopped spinach, thawed and squeezed dry; 1/4 teaspoon freshly grated nutmeg