In a large pot over medium-high heat, add a drizzle of olive oil and sear 1 pound of Italian sausage until deeply browned, about 6-8 minutes. Use a wooden spoon to break it into smaller pieces as it cooks. Transfer the sausage to a plate, leaving the remaining fat in the pot for flavor.

In the same pot, melt 2 tablespoons of unsalted butter over medium heat. Add 1 cup of mirepoix (chopped carrots, celery, and onions) and sauté until softened, about 5 minutes. Stir in 3 cloves of minced garlic and cook for an additional 30 seconds until fragrant.

Add 1 pound of halved baby gold potatoes to the pot along with 1 teaspoon each of dried parsley and basil. Pour in 6 cups of chicken stock and bring the mixture to a rolling boil. Once boiling, reduce heat to low, cover the pot, and let it simmer for 15-20 minutes, or until the potatoes are tender.

In a separate medium saucepan, melt 2 tablespoons of butter over medium heat. Whisk in 2 tablespoons of flour, stirring continuously for about 1-2 minutes to form a roux. Gradually whisk in 2 cups of milk, continuing to stir until the mixture thickens, about 5 minutes. Stir in 1 cup of heavy cream, then remove from heat.

Once the potatoes are tender, carefully stir the roux into the pot with the sausage potato soup. Gradually add 1 cup of shredded extra-sharp cheddar cheese, stirring until melted and smooth. Return the browned sausage to the pot and season with salt and pepper to taste.

Ladle the sausage potato soup into bowls, garnishing with a dollop of sour cream if desired for added creaminess. Serve hot, paired with hearty buttered bread for dipping, and enjoy!