Hi Guy's
Just a note on mustard oil, this is readily available from Asian supermarkets. The weird thing is, if you check the label on the back of the bottle, it will say "for external use only" I did ask the shop owner about this and he said that it was fine for consumption, and that he uses it in his tandoori marinades.
Just thought I would point that out incase you try looking for "edible mustard oil"
Ray