Lau said:but whether or not they use certain ingredients should be clear across the board from McDonalds to a £100 a head restaurant. Being snobbish about what restaurant it is is just, well, snobbish.
You've probably got more chance in McDs/chain restaurant of finding out exactly what ingredients are in a dish since they are mass-produced and standard portions than in an expensive restuarant where not only might the chef not want to disclose his secrets but where the menu varies so much, there's probably not a 100g contains x/y/z breakdown in existence. You might be able to ask your waiter to ask the chef to let you know if there are any milk products in your proposed dishes but I suspect that's about it.