Some airlines run an entire "special meal" service ie their meals would be considered "special" by any other airline.
For example, on El Al Israel airlines, all their food is strictly Kosher. However, you can still order vegetarian for example. But you'll get Kosher vegetarian. And of course, you can order "special" Kosher if you're not happy with the certification of the Rabbi who supervises their "regular" Kosher meals. Don't ask.
Interestingly, a number of charter airlines flying to Israel serve Kosher meals to everybody, although British Airways doesn't.
La petite mort says All of Emirates in flight meals are Halal.. I suspect this applies to other airlines based in Arab countries and no doubt some of them (albeit not Emirates) are dry too.