Drain canned chopped clams in a sieve and reserve the liquid. Cut two-thirds of the clams into small pieces. Clean and rinse the spring onions, and finely chop it up. Add all clams, clam liquid, spring onions, and cranberries into the soup and let it sit for a few minutes. Season again with salt and pepper. Add some more cooked clams to soup according to taste. Garnish with chopped parsley and serve.