Several years ago, I had a friend of Vietnamese descent. She went back to visit her home country and returned with gifts. I was given a box (possibly yellow) containing several foil-wrapped cubes or rectangles. They were a sort of caked or compressed powder, and somewhat unpleasant to eat. I have since lost touch with my friend, but I would love to be able to track down (or at least identify) this food.
I remember that the first ingredient listed was "grease pig."