I'll admit, this isn't exactly a quality picture (nor will this be much of a quality post), but it was taken in a dimly lit confined tube.
Anyway, we flew Air New Zealand both ways and I was pleasantly surprised by their gluten free meal offerings over the 13 hour flight. I got to select the special meal option when we booked our tickets and they stated that customers with severe reactions may not want to partake as they couldn't guarantee that cross contamination may have occurred in the production of the meals, so we brought enough of our own food in case it looked suspicious.
The picture above was my dinner from our first flight and consisted of a nice vegetable hash, salmon, potatoes, a salad, rice cakes, and a banana. On our flight back the dinner actually included a gluten free roll and breakfast included a gluten free rice cereal!
In general the meals were not much to brag about and I'm glad we brought some of our own food with us as well, but it was nice to get a couple of things to eat from the airline. So if you're flying Air New Zealand, you should have some options for a gluten free meal.