Cook the Pasta: Bring a large pot of salted water to a boil. Add the ditalini pasta and cook until just al dente, or about 1 minute less than the package directions. Drain the pasta and set it aside.
1 ½ cups uncooked ditalini pasta
Brown the Sausage: Place a large soup pot or Dutch oven over medium-high heat. Add the Italian sausage and cook until no longer pink, breaking it into bite-size pieces with a wooden spoon. Transfer the cooked sausage to a paper towel-lined plate and set it aside.
1 pound ground Italian sausage
Sauté the Vegetables: Add the olive oil to the same pot. Stir in the diced onion, carrots, and celery, then cook for about 5 minutes, until the vegetables start to soften. Add the garlic and cook for about 30 seconds, just until fragrant.
1 tablespoon olive oil, 1 ½ cups diced yellow onion, 1 cup diced carrots, 1 cup diced celery, 2 teaspoons minced garlic
Build the Soup: Pour in the chicken broth, tomato sauce, cannellini beans, kidney beans, diced tomatoes with their juices, Italian seasoning, salt, and black pepper. Stir everything together and bring the soup to a boil.
4 cups low-sodium chicken broth, 30 ounces tomato sauce, 15 ounces cannellini beans, 15 ounces dark kidney beans, 14 ounces canned diced tomatoes, 1 tablespoon Italian seasoning, ½ teaspoon salt, ¼ teaspoon black pepper
Simmer the Soup: Reduce the heat to a simmer. Add the cooked sausage and drained pasta back into the pot. Let the soup simmer for 10 to 15 minutes, until the flavors come together and the pasta finishes cooking in the broth.
Adjust the Texture: If the soup gets too thick, stir in a little more chicken broth until it reaches the texture you like. Taste and add more salt or pepper if needed.
Serve: Ladle the Pasta Fagioli with Italian Sausage into bowls. Top with grated Parmesan cheese and fresh chopped parsley. Serve warm with crusty bread.
Fresh chopped parsley, ⅓ cup grated Parmesan cheese