In a large pot, heat olive oil over medium heat.
Add diced onion and sauté for 3–4 minutes until translucent.
Stir in minced garlic, Italian seasoning, salt, pepper, and red pepper flakes. Cook for 1 minute.
Pour in chicken broth and bring to a boil.
Add broken lasagna noodles and simmer for 10–12 minutes, stirring occasionally, until noodles are tender.
Stir in shredded chicken and heavy cream. Simmer for 2–3 minutes.
Add mozzarella, parmesan, and spinach. Stir until melted and spinach is wilted.
Serve hot, garnished with fresh parsley if desired.