1. Heat a large pot over medium-high heat. Add sausage and sear for 1 minute, then crumble with a wooden spoon. Cook until deeply browned. Transfer to a plate lined with paper towels, leaving about 1 tablespoon grease in the pot. Add 1 tablespoon olive oil if needed.

2. In the same pot, melt 1 tablespoon butter. Add diced carrots, celery, and onion. Sauté for 5–7 minutes (or 7–10 minutes if larger). Add garlic and cook for 30 seconds more.

3. Stir in chopped potatoes, basil, parsley, salt, and pepper. Pour in chicken stock, bring to a boil, then reduce heat to medium-low. Cover and cook for 15–20 minutes or until potatoes are fork-tender.

4. While potatoes cook, melt 4 tablespoons butter in a separate medium pot over medium heat. Stir in flour and cook, whisking constantly, for 1 minute. Slowly pour in milk, whisking until smooth. Cook until thickened and gently boiling. Stir in heavy cream, then remove from heat.

5. Once veggies are tender, stir in the milk/cream mixture. Turn off heat and add shredded cheese, a handful at a time, stirring gently until melted.

6. Stir in sour cream, then return the sausage to the soup. Adjust seasoning with salt and pepper to taste.

7. Serve warm with hearty buttered bread if desired.