extra-virgin olive oil
yellow onion, chopped
celery stalks, chopped
cloves garlic, minced
red pepper flakes
Kosher salt
Freshly ground black pepper
chicken broth
Juice of 1/2 lemon
boneless skinless chicken breasts (about 3 large breasts)
(14-oz) can artichoke hearts, drained and quartered
shredded mozzarella
freshly grated parmesan, plus more for garnish
heavy cream (optional)
fresh spinach
freshly chopped parsley, for garnish