Near you
Same honest answer as the NEC (they're right next to each other): we don't currently have a verified halal restaurant near Birmingham Airport itself in our directory.
If you're flying out and want to eat halal before heading to the airport, Small Heath and Sparkbrook (roughly 15-20 minutes by car) are your nearest strong options — see the full directory. Inside the terminal itself, checking directly with airport food outlets for halal options or certification is worth doing, since this varies and changes over time.