In a large pot, heat a tablespoon of olive oil over medium heat. Add one finely chopped onion and two minced garlic cloves, stirring occasionally for about 3-5 minutes until the onions become translucent and the garlic is fragrant.

Increase the heat to medium-high and add one pound of ground Italian sausage. Cook for 5-7 minutes, breaking it apart with a spoon until browned and fully cooked.

Stir in a 28-ounce can of crushed tomatoes, 4 cups of chicken or vegetable broth, and 2 teaspoons of Italian seasoning. Bring to a gentle simmer over medium heat.

Carefully add 8 ounces of broken lasagna noodles and cook according to package instructions, usually around 10 minutes.

Once the pasta is cooked, reduce the heat to low and stir in 1 cup of ricotta cheese, cooking for an additional 2-3 minutes.

Ladle the warm soup into bowls and top each serving with shredded mozzarella cheese and croutons, if desired.