In a large pot over medium heat, add 1 pound of Italian sausage and cook until browned, about 5-7 minutes, breaking it apart with a wooden spoon. Next, stir in 1 chopped onion and 3 minced garlic cloves, cooking for an additional 2-3 minutes until the onion becomes translucent and fragrant.

Add 4 cups of diced potatoes and 6 cups of chicken or vegetable broth to the pot. Increase the heat to bring the mixture to a rolling boil, then reduce to a gentle simmer. Cover and let it cook for approximately 15-20 minutes, or until the potatoes are fork-tender.

Once the potatoes are tender, reduce the heat to low and slowly stir in 1 cup of cream, allowing it to blend smoothly with the soup. If including greens, add 2 cups of spinach or kale at this point, heating until they wilt.

Taste your sausage potato soup, adding salt and pepper as needed. You can also sprinkle in some red pepper flakes if preferred. Let the soup simmer for another 2-3 minutes to ensure everything is heated through.

Ladle the creamy sausage potato soup into bowls, serving it warm alongside crusty bread or a fresh side salad.