At the beach dig a hole in the sand with the approximate proportions: width = 1/2 metre, length = 1 metre, depth 1/2 metre. (Make sure its big enough to hold all your kai and the stones.) Line the hole with stones from the beach. Build a fire inside of the hole and cover with rocks from the beach. Heat the stones for 2 to 3 hours.
Remove coals and/or embers from the hole. Arrange hot stones evenly across the bottom of the hole. Place fresh 1/2 bushel seaweed (wet) on top of the hot stones.
Working quickly layer the food on top of the seaweed, the food should be layered evenly on top of each other in the following order: pipi, mussels, fish, sausages (wrapped in cheesecloth), onions, potatoes and kumara, corn and finally crayfish.
Cover food with a clean, wet cloth. Place remaining seaweed on top of cloth.
Cover entire hole of food with a wet tarpaulin, sealing the steam created by the hot stones and seaweed in. Allow a very small amount of steam to escape to relieve pressure. Let cook for 1 or more hours. The bake is completed when the potatoes are soft. Serve bake with melted butter to dip the seafood in and crackers. Don't forget serviettes -- you'll need 'em.
You can use any kind of shellfish you like.
Pipi is a New Zealand shellfish, but you can use any kind of clam.
Kumara is known in Australia as a sweet potato.
Crayfish is like a lobster.