Remove the sausage from the casing. Divide the meat from each sausage meat into four portions and roll into small meatballs. In the end, you should have 20 tiny meatballs.
Heat a large pot over medium-high heat. Once hot, add the olive oil, and fry the sausage on all sides until golden brown, about 5 minutes. Remove the sausage from the pot and set aside, but keep the oil in the pot.
Add the onion, salt, and pepper to the pot and cook for 3-4 minutes, or until the onion has softened and has become a light golden brown. Add the garlic and red chili flakes and cook for 30 seconds.
Add the white wine, rosemary, and sage to the pot. Use a wooden spoon to scrape all the brown bits off the bottom of the pot. Continue cooking over medium-high heat until the wine has reduced by half, about 5 minutes.
Add one can of the cannellini beans to the pot. Use a potato masher to break up the beans into a rough paste. Add the other can of beans (keep whole) and chicken broth to the pot and bring to a boil. Once the soup boils, add in the sausage balls, reduce the heat to low and let simmer for 25-30 minutes to allow the flavours to combine.
Stir in the kale right before serving so that it stays nice and green and does not get overcooked. Taste and adjust seasoning as needed.
Serve warm with a side of your favourite bread. Enjoy!