I’m making a vegetarian moussaka and the recipe I’m using just talks about a béchamel sauce on top.
Some of my older recipes I’ve got in a folder going back a few years talk about putting cheese either in the sauce or grating parmesan on top.
What would you do?
Grate parmesan on top.
I love cheese so would always put some on.
However, I think Moussaka has a hint of nutmeg in the bechemal sauce.
nana moussaka - she was a singer wasn’t she 
Vegetarian OH gets a bit fed up of cheese everywhere. So we put a bit of parmesan in top but stick to béchamel with the infused milk flavoured with bay leaf, cloves and mace/nutmeg.
As a vegetarian I must say I’m with Jane’s husband on this. There’s nothing more annoying than people sticking cheese in food for non-meat eaters to ‘give it some flavour’. There are plenty of ways of imbuing dishes with flavour - and in my view, very few of them necessitate the addition of cheese!