I had to eat here the other week with a large group as part of a meeting. It was my worst kind of situation as someone had prechosen all the dishes with no consultation. But the service was excellent - I spoke to the manager when we got there, and he told me to just wait until he put something in front of me, and he would ensure it was GF. And it was, and done very discreetly so I didn't have to explain to the people around me, or sit there waiting for food. The waiting staff just put down the 'normal' food in front of me, and then the manager just exchanged it.
It's not cheap, but the food was lovely, and I wanted to give them a big up for the service.
Orrery restaurant