Im not sure what recommended is but quite a few have GF menu's. 

One i use (because of the location) is a chain called La Tasca and they have quite a few GF items...  its just tapas but hey its food.. and I quite like tapas too! 

The important thing is they don't prepare the GF stuff onsite..for instance they have 2-3 GF paella's but these are individual porttions but the ones they make themselves though identical are not GF since they can't guarantee no contamination in the kitchen

It would be helpful to know if DS supply any resto's (and please try doing the Eurostar their GF bread is like cardboard) because I would view that as a good sign and patronise that resto if I could! 

We are working closely with Compass one of the UK's largest food service suppliers to try and get more gluten-free foods on their menus. I am also trying to persuade Pizza Express to offer one of our frozen pizzas in their restaurants, but it is proving an up-hill struggle at the moment.

Hopefully events like this Coeliac Awareness Week will improve the need to provide better catering and undertsanding of gluten-free food in restaurants.

Keep an eye on the new Coeliac UK website www.gluten-free-onthego.com More restaurants should sign up on this website soon.

Hmm seems like it is going to favor larger chains...

As expected they have to pay to 'advertise'... 

Annual (12 months) £100 + VAT