In a large saucepan or stockpot, heat over medium-high heat and cook the Italian sausage, breaking it up as it cooks using a wooden spoon. Continue cooking until the sausage is no longer pink, which usually takes about 7 minutes.
Next, add the onions, oregano, carrots, garlic, spinach leaves, diced tomatoes with their juices, canned beans and pasta to the saucepan. Stir the ingredients together until they are well combined.
Now add dry basil, celery and season the mixture with salt and pepper to your liking. Proceed to pour in the chicken broth and bring the soup to a simmer.
After achieving a simmer, reduce the heat to medium and let the soup simmer uncovered for about 20 minutes, or until the pasta reaches the desired tenderness.
Finally, serve the soup hot, topped with freshly grated Parmesan cheese and a side of crusty bread.