Wash and peel the ginger, slice it thickly, and lightly crush the slices with the flat of a knife.
Fry the ginger in hot oil with a little salt for about 5 minutes, then set aside.
Singe and scrape the trotters to remove any hair, then blanch in hot water until the skin tightens and changes colour; rinse with cold water, and let drain.
Cut the drained trotters into pieces, rub with salt, and brown all over in their own fat in a hot pan or wok.
Put the ginger and trotters into a clay pot, add the vinegar, bring to a boil, then cover and simmer gently for 20 minutes.
Add the boiled eggs, and simmer for another 10 minutes.
Remove from the heat, and let stand for a day, warming it through and letting it cool a few times in between, so the flavours meld fully and the sauce sets into a jelly.