"Skip the oven with this Chicken Alfredo Lasagna Soup from Delish.com...."
extra-virgin olive oil
medium onion, chopped
stalks celery, chopped
cloves garlic, minced
freshly chopped thyme
crushed red pepper flakes
Kosher salt
Freshly ground black pepper
butter
all-purpose flour
low-sodium chicken broth
chicken breasts (about 3), cut into thirds
lasagna noodles, broken into 2" pieces
heavy cream
shredded mozzarella
freshly grated Parmesan, plus more for serving
loosely packed spinach
chopped parsley, for serving