Step 1: Heat olive oil in a large Dutch oven or pot over medium-high heat. Add ground beef (or sausage) and cook, breaking it apart with a spoon, until browned. Drain any excess fat.
Step 2: Add chopped onion to the pot and cook until softened, about 5-7 minutes. Stir in minced garlic, Italian seasoning, and red pepper flakes (if using). Cook for another minute until fragrant.
Step 3: Stir in the tomato paste and cook for 2 minutes, stirring constantly, to deepen its flavor.
Step 4: Pour in the crushed tomatoes, beef broth, and tomato sauce. Bring the mixture to a simmer, then reduce heat to medium-low, cover, and let it gently simmer for 15 minutes to allow the flavors to meld. If desired, stir in heavy cream for a richer, creamier broth.
Step 5: While the soup simmers, prepare the ricotta dollop: In a medium bowl, combine ricotta cheese, Parmesan cheese, egg yolk, nutmeg, salt, and pepper. Mix until well combined and smooth.
Step 6: Uncover the soup, add the broken lasagna noodles, and cook for 8-10 minutes, or until the noodles are al dente. Stir occasionally to prevent sticking. The noodles will absorb some of the liquid, so if the soup becomes too thick, add a little more broth.
Step 7: Stir in the fresh basil. Taste and adjust seasoning with salt and pepper as needed.
Step 8: Ladle the hot Lasagna Soup with Ricotta Dollop into bowls. Top each serving with a generous dollop of the seasoned ricotta mixture, a sprinkle of shredded mozzarella, and additional fresh basil or parsley. Serve immediately and enjoy your homemade Lasagna Soup with Ricotta Dollop!