i think a mixture of both light and dark...
some stock..
the lard part mentioned by neuros is actually rendered lard... the
melt the pork fat until there's just oil... then they use the oil
to fry up some shallots and garlic which is added...
also, there's their recipe for chilli.. that, is usually something
they keep secret if it is very good...
there's also a touch of sesame seed oil...