Cook the Sausage:
Remove the sausage from its casing and add it to a large pot or Dutch oven over medium heat. Use a wooden spoon to break it up as it cooks, sautéing until it’s browned and cooked through.

Add the Onion and Garlic:
Add the chopped onion and minced garlic right into the same pot with the sausage. Sauté for a couple of minutes until the onion softens and the garlic is fragrant.

Add the Tomatoes, Broth, Beans, and Seasoning:
Pour in the crushed tomatoes and chicken broth. Drain the cannellini beans and add them to the pot. Stir in the salt, black pepper, oregano, red pepper flakes, and basil leaves, mixing well to combine all the flavors.

Boil the Pasta:
While the soup is coming together, bring a large pot of salted water to a boil for the pasta. Cook the Ditalini according to package directions, then drain and set aside.

Simmer and Add Spinach:
Bring the soup to a gentle boil, then reduce the heat and let it simmer for 30 minutes to allow the flavors to meld. Stir in the fresh spinach and remove the pot from the heat.

Serve with Pasta and Broth:
Divide the cooked Ditalini pasta into bowls, then ladle the hot soup broth with sausage, beans, and spinach over the pasta. Top each serving with grated Parmesan cheese.