In a large pot, over medium-high heat, add the Italian sausage. Cook for 5-7 minutes, stirring occasionally, until it is nicely browned and cooked through. Once browned, drain any excess fat.

Reduce the heat to medium and melt the unsalted butter in the same pot. Add the mirepoix and cook for 5-10 minutes until the vegetables begin to soften. Stir in the minced garlic and sauté for an additional 30 seconds.

With the mirepoix ready, add the baby gold potatoes, dried parsley, dried basil, salt, and pepper. Pour in the chicken broth and bring the mixture to a boil. Once boiling, reduce the heat to low, cover, and simmer for 15-20 minutes.

In a separate pan, prepare a roux by melting some butter over medium heat and whisking in the flour for about 2 minutes. Gradually whisk in the milk and cook for another 5 minutes until thickened.

Carefully mix the prepared roux into the soup, stirring to ensure it combines smoothly. Next, add the extra-sharp cheddar cheese and sour cream, stirring until the cheese melts.

Ladle the Creamy Sausage Potato Soup into warm bowls. Garnish with fresh herbs and serve with hearty buttered bread for dipping.