Wash lu'au leaves, remove stems and thick veins. In a pot, boil 3 cups of water with the rock salt, and baking soda. Add the leaves to the boiling water and reduce heat. Simmer, partially covered, for 1 hour. Drain, and squeeze out liquid.
Saute' onions and calamari in butter until the onions are translucent. Add the coconut milk, cooked lu'au leaves, salt, and sugar. Simmer for 30 minutes.