I am currently tucking into a mince and onion pie made with fake mince...very nice.
A few things....
Obviously don't use worcester sauce, Bovril or Beef oxo to make the taste more meaty if you are cooking for a veggie. You can use veg oxo, HP sauce or marmite to taste.
Also, if you haven't bought the Quorn yet, I recommend 'Real Eat' veggie mince, which is imho nicer and has a better texture. Also, althought you don't have to cook the mince for as long as you have to cook meat, the longer you cook it, the more flavour the mince has.
Vicky