Step 1: Brown the Sausage. In a large Dutch oven or heavy-bottomed pot over medium-high heat, brown the Italian sausage, breaking it up with a spoon as it cooks. Once fully cooked and no pink remains, drain off all but about 1 tablespoon of the fat. This foundational step ensures your creamy sausage and potato soup has a rich, deep flavor.
Step 2: Sauté Aromatics. Add the chopped onion and minced garlic to the pot with the remaining sausage fat. Sauté for 3-5 minutes, until the onion softens and becomes translucent, and the garlic is fragrant. Be careful not to burn the garlic!
Step 3: Build the Roux. Sprinkle the flour over the cooked sausage and aromatics. Stir continuously for 1-2 minutes, allowing the flour to cook out its raw taste. This creates a roux, which will thicken our creamy sausage and potato soup beautifully.
Step 4: Deglaze and Add Broth. Slowly pour in the chicken broth, whisking constantly to prevent lumps. Bring the mixture to a gentle simmer, scraping up any browned bits from the bottom of the pot. These 'fond' bits add immense flavor to your creamy sausage and potato soup.
Step 5: Add Potatoes and Seasoning. Stir in the diced potatoes, bay leaf, dried thyme, salt, and black pepper. Bring the soup back to a simmer, then reduce the heat to low, cover, and cook for 15-20 minutes, or until the potatoes are fork-tender.
Step 6: Stir in Cream and Cheese. Once the potatoes are tender, remove the bay leaf. Reduce the heat to its lowest setting. Stir in the heavy cream and shredded cheddar cheese (if using). Cook for another 5 minutes, stirring occasionally, until the cheese is melted and the soup is heated through and wonderfully creamy. Do not let the soup boil once the cream is added. This is where the magic happens, transforming it into a truly luxurious creamy sausage and potato soup.
Step 7: Taste and Adjust. Taste the soup and adjust seasonings as needed. You might want a little more salt, pepper, or even a pinch of red pepper flakes for a subtle kick.
Step 8: Garnish and Serve. Ladle the hot soup into bowls. Garnish with fresh chopped parsley or chives, and a sprinkle of extra cheese or crispy bacon bits, if desired. Serve immediately and enjoy your hearty bowl of creamy sausage and potato soup!