In a Dutch oven, sauté the sausage, mushrooms and onion over medium-high heat until sausage is fully cooked and vegetables are tender/onions are a slightly translucent, about 8-10 minutes. Break the sausage into crumbles and drain off any excess fat/liquid. Add in garlic and cook for another minute.
Add chicken stock/broth, pumpkin puree, sugar and seasonings. Bring to a boil and then reduce heat. Cover and let simmer for 10 minutes.
Stir in the cream and chopped kale. In a small bowl, whisk together the water and cornstarch until smooth. Stir into the pan and bring to a boil. Cook stirring frequently until the soup thickens, about 1-2 minutes. Add the cheese and cook just until melted. Serve and enjoy!