I liked the Cottage Pie they did in CW about 18 months ago - not exactly gourmet, but worked well for an "airline meal" (i.e. something simple done well, rather than something complicated done badly...).
That was ex-LHR. Shame that they haven't bought the Cottage Pie back... definitely better than some of the other things on offer.
Agree that BA isn't the best. Was pretty impressed with the CO BusinessFirst meal service (LGW-IAH) a few years ago: a lot of the food (appetisers, desserts/sundaes AND cheese & biscuits) are served from trolleys - so you can choose what (and as much as) you like.
Boo