Heat the olive oil in a large pot or Dutch oven and add the onion. Cook until it’s soft, then add the beef and sauté. Once the beef is browned all over, stir in the garlic, red pepper flakes, 1 teaspoon of kosher salt, oregano, and tomato paste. This initial step is crucial for building the soup's flavor foundation, ensuring that the beef is well-seasoned and aromatic.

Stir in the tomato sauce, diced canned tomatoes, and chicken broth. Bring it to a boil, then add the broken lasagna noodles to the pot. Add the remaining 1 teaspoon of kosher salt, or more to taste. Reduce the heat and let it simmer until the noodles are tender. This simmering time allows the noodles to soak up the flavors, becoming soft and luscious.

Stir in the heavy cream. You can add 1-2 cups extra chicken broth at this point to help thin it out if you want a thinner soup. Pro tip: Stir shredded mozzarella or parmesan right into the soup to make it extra creamy and cheesy! This step is where you can customize the creaminess to your preference.

Spoon the lasagna soup into bowls and add ricotta cheese, mozzarella cheese, and parmesan cheese along with fresh basil on top. Serve and enjoy! The garnishes not only add flavor but also create a delightful contrast in textures.