In a large pot over medium-high heat, add the Italian sausage. Sear it while breaking it apart with a spoon for 5-7 minutes, or until browned and cooked through. Remove sausage and set aside, reserving the grease.

In the same pot, melt 2 tablespoons of unsalted butter over medium heat. Add the mirepoix mixture, sauté for 5-10 minutes until softened and fragrant. Stir in minced garlic and cook for an additional 30 seconds.

Stir in the chopped baby gold potatoes, parsley, basil, salt, and pepper. Pour in the chicken stock, bring to a boil over high heat, then lower heat to simmer, covering for 15-20 minutes until the potatoes are fork-tender.

In a separate pot, melt the remaining 2 tablespoons of unsalted butter over medium heat. Whisk in the flour and cook for about 1 minute to create a roux. Gradually add the milk and whisk to prevent lumps, cooking until thickened. Stir in the heavy cream and remove from heat.

Once potatoes are cooked, lower heat and gently stir in the cream mixture and shredded cheese, allowing it to melt. Add cooked sausage back, adjust seasoning with more salt and pepper. Serve warm with hearty buttered bread.