In a large pot, sauté sausage 5–6 minutes until browned. Use a slotted spoon to transfer sausage to a plate and set aside.
In the same pot, add butter and sauté onions over medium heat until translucent. Add garlic and cook for another minute until fragrant.
Add chicken broth, water, potatoes, salt, and pepper. Bring to a boil and cook until potatoes are tender. Stir in kale and heavy cream. Add sausage back to the pot. Taste and add salt and pepper if needed.
Serve garnished with grated Parmesan cheese and/or bacon if desired.