Bring a pot of salted water to a boil. Cook the pasta until al dente, then drain.
While the pasta is cooking, heat the olive oil in a deep-sided skillet over medium heat. Add the sausage to the skillet, and cook for about 7 minutes, or until it is brown on all sides. Set aside on a cutting board to rest.
Add the butter to the skillet and lower the heat. Add the onions and sauté for 3-5 minutes, then add garlic, and cook for about 30 seconds more. Stir in the kale and season lightly with salt and pepper.
While the kale wilts, slice the sausages into 1 inch pieces and add to the skillet, along with the cannellini beans.
Add the pasta to the skillet, along with about 1/2 cup of the chicken broth and the grated Parmesan. If the pasta needs a little more sauce, add a little more chicken broth.
Season to taste with salt and pepper and serve immediately with grated Parmesan on the side.