A soup made from toheroa, that sadly, is fast becoming an unknown delicacy in New Zealand due to a permanent 'closed season' for gathering the shellfish. As I remember, the soup is a delectable green, with a distinctive satin-smooth shellfish taste. The closest you'll get to it now is tuatua or pipi soup.
Toheroa Soup
1 dozen toheroa
1 litre (2 pints) milk
25g (1 oz) butter
salt and pepper
Mince toheroas. Cook in 600ml (1 pint) of milk until soft (about 1/2 hour). Rub through a coarse sieve; add remainder of milk, butter and salt and pepper. Just before serving, thicken with a little mixed cornflour.
recipe from: Edmonds Cookery Book