Recently I flew Delta, SFO to JFK in first class and special ordered a Muslim meal for lunch.

Much to my surprise it was a quite tasty chicken curry dish with basmati rice. I had just expected a generic vegetarian meal with a "MOML" sticker...

The meal came with a card that said something like "This _____ meal prepared by request" where it had the world "Muslim" written in by hand.

My experience in coach (int'l flights since domestic coach never gets meals on Delta) is they do just give you a vegetarian meal.