Here is a list of restaurant chains that seem to know and understand about coeliac disease

They also have good vegetarian and vegan options on the menu.

Zizzi

Zizzi is a popular italian chain, found in most high streets.

Their staff are knowlegable about coeliac disease and gluten free.

You can find Zizzi on most high streets - check out their site for more info

Pho cafe

This is a chain of vietnamese restaurants. Almost everything on the menu is gluten free (one of the main ones which are not gluten free are spring rolls). Lots of vegan options. Their staff understand coeliac.

Pho cafe are all over London, and in many other cities in the UK. Visit their site

Ask italian

Another Italian restaurant chain, found on many high streets. Very knowledgeable about gluten free food, and they have many options available.

You can find Ask Italian in most large towns. Visit their site

Pizza express

Pizza express is a really nice chain, again found on many high streets. They, would you belive it, specalise in pizzas. Lots of gluten free options.

Pizza Express are in most towns - find one near you via their site