Sauté - In a large pot, heat olive oil over medium heat. Add the chopped onion and cook for 3–4 minutes until softened. Stir in minced garlic and cook for 30 seconds until fragrant.
Add tomato paste- Stir in the tomato paste and cook for about 1 minute to “toast” it. This step deepens the tomato flavor and removes any raw taste.
Brown the meat- Add ground beef and Italian sausage to the pot. Cook until browned, breaking it up as it cooks. Drain excess grease if needed.
Build the base- Pour in tomato basil sauce and beef broth. Stir well, scraping up any bits from the bottom of the pot. Season with salt, pepper, red chili flakes, and Italian seasoning.
Simmer- Bring the soup to a gentle boil, then reduce heat to low and simmer for 15–20 minutes to let the flavors develop.
Cook the noodles- Add the broken lasagna noodles directly into the soup and cook until tender, about 10–12 minutes. Stir occasionally so they don’t stick together.
Make it creamy- Stir in the heavy cream and let simmer for another 3–5 minutes until rich and silky.
Prepare the ricotta mixture- In a small bowl, mix together ricotta cheese, parsley, and Parmesan until smooth.
Serve- Ladle the soup into bowls, top with a spoonful of the ricotta mixture, and place a slice of fresh mozzarella on top. Let it melt slightly before serving.