Cook the sausage: Heat olive oil in a large pot over medium heat. Add Italian sausage, break it up, and cook for 5-7 minutes until browned. Remove excess fat if desired.
Sauté the aromatics: Add diced onion and sauté for 3-4 minutes until softened. Add minced garlic and sauté for 30 seconds until fragrant.
Add broth and noodles: Pour in chicken broth, stir in broken lasagna noodles and Italian seasoning. Bring to a boil, then simmer for 10-12 minutes until noodles are al dente.
Incorporate Alfredo sauce: Stir in Alfredo sauce and heavy cream. Simmer for 3-5 minutes to meld flavors.
Add greens and cheese: Stir in spinach or kale and cook for 1-2 minutes until wilted. Add Parmesan cheese and stir until melted. Adjust seasoning with salt, pepper, or red pepper flakes.
Serve and garnish: Ladle into bowls, dollop with ricotta (if using), and sprinkle with parsley and extra Parmesan. Serve with crusty bread.