Remove the husks from the 4 small coconuts and carve them into the shape shown in the drawing, using a very sharp knife. Cut off the top of each, in the form of a dome-shaped cap, to open the contents. Pour out the coconut water, but do not disturb the meat.
Mix together the lightly beaten eggs, the sugar and the thick coconut milk. Pour the mixture into the small coconuts, set their caps on them and steam them for about half an hour, until done.