Kosher has stricter standards such as no mixing of meat and dairy, but does allow alcohol. Muslims could eat kosher food as long as a few minor points were addressed, so possibly a simple dual rated menu could be produced which meets whichever requirements are more restrictive.
Ordering kosher is often a good option on a flight as your meal gets served first. Most institutions are unable to obtain kosher certification for their kitchens and have to order from outside suppliers. A Jew serving time in a British prison is entitled to food which meets religious requirements and will eat far better than those with no special dietary needs.