Begin by dicing the large onion, chopping the carrots and celery, mincing the garlic, and cubing the red potatoes. Aim for uniform pieces to ensure even cooking, particularly cutting the potatoes into 3/4-inch cubes. Set aside the prepared vegetables.

In a large pot, heat over medium-high heat and add the Italian sausage. Cook for 10–12 minutes, breaking it apart with a wooden spoon, until browned and fully cooked. Drain excess grease and set the sausage aside.

Using the same pot, melt 3 tablespoons of butter over medium heat. Add the diced onion, chopped carrots, and celery, sautéing for about 5 minutes until softened. Stir in the minced garlic and cook for an additional minute.

Sprinkle the 3 tablespoons of flour over the sautéed vegetables in the pot, stirring continuously for 2 minutes.

Gradually pour in the 6 cups of chicken broth while continuously stirring. Add the heavy cream, 1 teaspoon of soy sauce, and 1.5 teaspoons of hot sauce. Mix in the dried seasonings.

Bring the soup to a gentle boil over medium-high heat, then reduce to medium-low. Add the cubed red potatoes and let simmer for 20-25 minutes until tender.

Stir in the cooked sausage, allowing it to warm through. Remove from heat and gradually mix in the 2.25 cups of freshly shredded cheddar cheese.