Even if you book a veggi meal they will still ask whether you want the beef, chicken or vegeterian pasta so it doesn't really make any difference. I still reserve one in advance though just in case, although it is not essential. BD don't screw you like other airlines. I ordered a dairy vegi meal on UA the other week and even though they had a veggi pasta option on the normal meal service I got something completely different and much less tasty. I also wasn't allowed any ice cream (I did book a VLML dairy meal) and had to beg for a tub. I was told I could have one if there were any left after all the other pax had been served. Luckily there was a spare. sometimes it is better not to order a vegi meal but with BD it makes no real difference.