In a large pot, cook and crumble the ground Italian sausage over medium heat for about 10-12 minutes, until browned. Reserve 1 tablespoon of the drippings in the pot and discard the rest.

Add the reserved drippings and 2 tablespoons of butter to the pot. Sauté the diced onion, carrots, and celery over medium heat for about 5 minutes, or until softened and the onions become translucent. Stir frequently.

Stir in the minced garlic and cook for 1 minute until fragrant. Then sprinkle in the flour and cook for an additional 2 minutes to form a roux, stirring constantly to prevent browning.

Gradually add the chicken broth in splashes while using a silicone spatula to scrape the bottom of the pot. This helps to incorporate the roux evenly and lift any browned bits for flavor. Stir until smooth with no clumps.

Add the cubed red potatoes and bring the soup to a gentle simmer. Cook uncovered for approximately 20-25 minutes until the potatoes are fork-tender and releasing their starches into the broth.

Stir in the heavy cream. Add 1 teaspoon each of soy sauce and hot sauce to enhance the flavor. If using, stir in shredded cheddar cheese until melted and combined. Heat through gently before serving.