In a large pot, heat over medium heat and add the ground Italian sausage, browning it for 10-12 minutes.

Add the reserved fat along with 2 tablespoons of butter to the pot, heating it over medium heat. Toss in the diced yellow onion, finely chopped carrots, and celery, sautéing for about 5 minutes.

Stir in 3 cloves of minced garlic and let it cook for 1 minute. Sprinkle in 1/4 cup of flour, stirring continuously for 2 minutes.

Gradually whisk in 4 cups of chicken broth while scraping the bottom of the pot. Bring the mixture to a gentle simmer.

Add 4 cups of cubed red potatoes to the pot. Increase the heat slightly to bring the soup to a low boil, then reduce to a simmer. Cook uncovered for 20-25 minutes.

Once the potatoes are tender, stir in 1 cup of heavy cream, 2 tablespoons of soy sauce, and a few dashes of hot sauce.

Ladle the soup into bowls and, if desired, top with optional shredded cheddar cheese.