A Macau-style sandwich: a thin, greasy slice of deep-fried pork topped 
with tons of onions and sandwiched between a roll with a crunchy crust.  
Once you bite through the crust, the sandwich kind of melts as onions and 
pork fat into your mouth.  Di Yin called it yummy.  It reminded me of 
typical (overly-greasy) fast food.