In a large saucepan, over medium heat, add the potatoes, onions, and garlic. Season with salt and pepper. Cover with water and bring to a boil. Reduce the heat to a simmer and cook until the potatoes are very tender, about 15 to 20 minutes. Remove the center rib of each piece of kale. Place the leaves of kale on top of each other and roll up tightly. Using a sharp knife, chiffonade or cut the kale into very thin strips. Using a hand-masher, mash the potatoes in the cooking liquid until smooth. **Add a little more water if the soup is too thick. Add the kale and continue to cook just long enough to wilt the kale. Stir in the olive oil. Taste, season with salt and pepper. In a saute pan, over medium heat, sear the sausage for a couple of minutes on each side. Remove the sausages from the pan and set aside to rest for a few minutes before slicing. Ladle the soup into each serving bowl. Garnish with a couple of the sausage pieces. Serve warm.