
In a 6-quart or larger pot set over medium heat, brown the ground sausage, crumbling into small pieces as it cooks. Cook until no longer pink. With a slotted spoon, remove the sausage to a paper-towel lined plate leaving about 1 tablespoon drippings in the pot.
Set the pot over medium heat and add the butter. Once melted, add the carrots, onions and celery. Cook until the onions begin to turn translucent, 3 to 4 minutes.
Stir in the chicken bouillon paste, garlic, basil, oregano, and parsley. Cook for 30 to 45 seconds, stirring constantly.
Add the potatoes, broth, salt and pepper. Stir to combine (scrape the bottom of the pot thoroughly). Bring the mixture to a boil. Reduce the heat to a simmer and cook for 15 to 20 minutes until the potatoes are tender, stirring often.
In a blender, combine the milk and flour. Process until smooth.
Pour the milk mixture into the soup. Bring the mixture to a simmer, stirring constantly, and cook for 4 to 5 minutes until thickened.
Add the cooked sausage to the soup and stir to combine.
Reduce the heat to medium-low. Stir in the cheese a handful at a time, and warm through until the cheese is melted. Season to taste with additional salt and pepper, if needed.
Serve the soup with oyster crackers, extra shredded cheese, and fresh parsley, if desired. The soup will thicken more as it cools.