In a large soup pot heat olive oil and sauté onion and garlic until vegetables are wilted, about 4 minutes. Add potatoes and chicken stock and bring to a boil. Season with salt and pepper, reduce heat to a simmer and cook, covered, until potatoes fall apart, about 1 hour. (To speed up this process, the potatoes can be mashed with a potato masher.)
While the soup is cooking, roll the kale leaves so that they may be inserted into a meat grinder or shredder fitted with a small die and finely grind the kale. (Altnerately, they can be shredded in a food processor fitted with a shredder blade.) Set aside.
When the soup is thick and the potatoes have broken up, whisk to break up the remaining potato pieces. Add the sausage and cook for 15 minutes. Stir in the shredded kale and simmer until the leaves are softened but still slightly crunchy and flavors have melded, about 10 to 15 minutes. Stir in the parsley, cilantro and mint and season to taste with salt and pepper.
Serve with crusty bread.
Yield: 4 to 6 servings