c'mon 'in the kitchen', drag yourself into the 20th century (the 21st might be a step too far
) 500g is probably GR's way of saying a pound, though it won't matter much.
I'm with Lynan, Shepard's pie is very well defined, it's only you Americans that seem h*ll bent on messing everything up. If you put cheese on a shepard's pie, you get Cumberland pie (I live in Cumberland
), and if you want to put beef and corn in your pie, then call it sumit else, and leave our shepard's pie alone!
Note that I'm not criticizing the pie, just what you call it.