In a large pot, brown the ground beef with chopped onion over medium heat, breaking it up as it cooks. Once browned, add the garlic and cook for another 1-2 minutes until fragrant.
Add the crushed tomatoes and beef broth to the pot. Stir to combine and bring to a boil. Once boiling, reduce heat and simmer for 10 minutes to allow the flavors to meld.
Add the broken lasagna noodles to the pot and cook for about 10-12 minutes, or until tender. Stir occasionally to prevent the noodles from sticking.
Stir in ricotta cheese and mozzarella until melted and combined. Adjust seasoning with salt and pepper to taste.
Serve the soup hot, garnished with fresh basil and additional Parmesan cheese if desired.
Notes
For a more indulgent version, top the soup with additional shredded mozzarella and broil until golden and bubbly.