My understanding is that on the DXB route [while it lasts], Virgin have never served meals containing alcohol or pork, or any derivatives of either. e.g. the sausages & bacon offered at breakfast are both turkey - and very nice, it has to be said. There may be other ingredients in some meals that some Muslim passengers may not wish to consume, but Virgin are avoiding the big two no-no's.
I know Emirates openly state that all their meals across their entire network are Halal.
Having worked with some excellent colleagues who are Muslim, I know there are different levels of compliance with the dietary rules. None would touch pork or alcohol, obviously. However some would eat the holiday sweets I used to bring back (fruit chewy sweets), whilst others would abstain as they contained bovine gelatine. (I just started bringing back a pack or two of chocolate biscuits for them instead, which was fine).
The only way the OP can find out what is in the food is to ask the crew for the ingredients / allergen list, which they will be happy to provide.