Combine squash, 1 cup broth, milk, and garlic in a medium saucepan; bring to a boil. Reduce heat to medium; simmer until squash is tender (about 20 minutes). Remove from heat.
Place squash mixture in a blender. Add salt, pepper, and nutmeg. Remove center piece of blender lid (to allow steam to escape); secure blender lid on blender. Place a clean towel over opening in blender lid (to avoid splatters). Blend until smooth. Place blended squash mixture in a bowl; add Gruyère cheese and 5 ounces mozzarella cheese, stirring until cheese melts and mixture is smooth.
Heat a large skillet over medium heat. Add oil to pan; swirl to coat. Add onion and mushrooms; cook 7 minutes or until browned and liquid evaporates. Add chard and remaining 1 tablespoon broth. Cover and cook 2 minutes or until chard wilts. Place chard mixture in a fine sieve; drain 5 minutes. Place chard mixture in a bowl. Add pine nuts; toss to combine.
Spread 1/2 cup squash sauce in bottom of a broiler-safe 11 x 7-inch glass or ceramic baking dish coated with cooking spray. Arrange 3 noodles over sauce; top with half of chard mixture. Dollop ricotta cheese on top of chard. Spread half of remaining sauce over top. Arrange 3 noodles over sauce. Top with remaining chard mixture; top with remaining sauce. Sprinkle evenly with remaining 5 ounces mozzarella cheese and Parmigiano-Reggiano cheese. Cover with foil coated with cooking spray. Bake at 375° for 35 minutes. Uncover and bake an additional 10 minutes or until bubbly.
Preheat broiler to high. (Keep lasagna in oven.)
Broil lasagna 3 minutes or until cheese is golden brown. Remove from oven; let stand 10 minutes.
I thought this was a lot of work but it was nice to have something different. I used egg lasagna noodles and was very happy with their firm texture. All of the flavors are very mild except the chard which my husband felt overpowered the dish. I might try spinach next time for less bitterness.
Definitely not a great dish if you are short on time - there are many steps and stages. But the outcome is worth it. I think leftovers will be even tastier. I did sub chicken broth for the veggie broth because it was what I had on hand.
I love butternut squash and I really wanted this to be good but it just wasn't. It was bland and the pine nuts seemed out of place. Especially for the time it took to make, I wanted it to be delicious. I won't make again.
This is delicious and creamy. I will make it again! I have never found a vegetarian lasagna that I really thought was worth making because they are all so full of fat and calories (no advantage!!!) This is the exception! It takes a while to put together but so does most any lasagna. I tasted the sauce before layering so that I got the saltiness just right for my family's taste. I also added shredded carrots for some color and heartiness. In addition, I put ricotta on both layers even though the recipe said only on the first. I'm not sure if this was an oversight or intentional but I still used the same total amount.The only negatives to this recipe may be the season availability of butternut squash vs the price and the price of the aged guyre cheese. It is absolutely essential though to the flavor of this dish!