Bring the chicken stock to the boil in a large, heavy saucepan. Add the potatoes, chourico and garlic. Simmer gently for 30 minutes or until the potatoes are soft.
Remove the chourico and when it's cool enough, slice diagonally into very thin slices.
With a potato masher, mash the potatoes right in the soup pot. They will end up in little chunks. Boil for 5 minutes.
While the potatoes are boiling, shred the kale. Gather some leaves together, roll them the long way, then cut the rolls into fine shreds.
Bring the soup to a furious boil. Add the kale and cook for 5 minutes or until it is just tender. Add the chourico slices and the salpicao and taste the soup for seasoning. Let simmer very gently for 5 minutes before serving in soup bowls. Drizzle each bowl with a little Portuguese olive oil.