In a large pot over medium-high heat, cook the Italian sausage until it’s fully browned, breaking it apart as it cooks. Scoop the sausage out with a slotted spoon, leaving about one tablespoon of the rendered fat in the pot, and discard the rest. Rinse the sausage briefly in a strainer to remove extra grease, then set aside.
Add the diced onions to the pot along with the reserved fat and sauté for about 5 minutes until softened, stirring occasionally. Stir in the minced garlic and cook for another minute to release its aroma.
Pour in the diced potatoes and chicken stock, then return the cooked sausage to the pot. Bring the mixture to a gentle simmer, then reduce the heat to medium-low. Let it cook uncovered for 10 minutes, or until the potatoes become tender.
Mix in the chopped kale and heavy cream, letting the soup simmer for an additional 5 minutes to combine the flavors. Season with salt and freshly ground black pepper according to your taste.
Ladle the soup into bowls and top with the crumbled crispy bacon before serving warm.
