In a large soup pot over medium-high heat, Add the ground sausage and cook, breaking it into small pieces as it cooks, until browned. Remove some of the grease and move sausage to one side of the pan.
Add chopped onions, garlic, and potatoes and sauté for a few minutes. Pour in chicken broth and water and allow mixture to come to a boil.
Reduce heat to medium low and cook until potatoes are fork tender, about 8-10 minutes.
Stir in the bacon, chopped kale, and cream. Season with salt and pepper and crushed red pepper flakes, if using. Cook for 2-3 more minutes or until warmed through.
Kale: You could also use spinach.Slow Cooker Instructions: Sauté ground sausage, onion, garlic and potatoes in a pan, then add to the slow cooker with water and broth. Cook on LOW for 5 hours or HIGH for 3, or until potatoes are tender. Stir in cream and season to taste.Instant Pot: Use the Instant Pot to sauté the sausage, onion, garlic and potatoes on sauté setting. Turn pot off and add water and broth. Cook on High pressure for 4 minutes, with a 10 minute natural release. Stir in kale and cream. Season to taste with salt and pepper.Make Ahead Instructions: The entire soup can be made 1-3 days ahead of time, stored in the fridge.Freezing Instructions: To freeze Zuppa Toscana, make the soup according to instructions but don't add the cream and don't cook the potatoes until tender. Allow soup to cool, then store in a freezer safe container for up to 3 months. Thaw overnight in the fridge and rewarm on the stove, cooking potatoes until tender, and then stir in cream.