In a large pot or Dutch oven, brown the ground beef or Italian sausage over medium heat. Drain off any excess grease.
Add the chopped onion and minced garlic to the pot and cook until softened, about 5 minutes.
Stir in the crushed tomatoes, tomato sauce, chicken broth, Italian seasoning, salt, and pepper. Bring to a boil, then reduce heat and simmer for 15 minutes.
Add the broken lasagna noodles to the pot and continue simmering until the noodles are tender, about 10-15 minutes.
Stir in the grated Parmesan cheese.
Serve the soup and garnish each bowl with shredded mozzarella cheese.