For a celiac, restaurant food is the equivalent of 'one man's food being another man's poison' since foods as disparate as dark soy sauce, cakes and health drinks contain gluten. So the celiac's risk of ingesting gluten increases radically though they do feel that eating out is well worth not only for the convenience but also for the social aspects.
As far as dining out is concerned, a celiac and restaurant chef require to interact so that the chef can serve up a 'safe' meal. In case the chef understands the problem and is willing to go the extra mile, a celiac can enjoy a meal safe for him as well as enjoy the ambiance and the convenience. Otherwise, there is no other option than to enjoy the company and the ambiance ... and go home and cook! Or eat well at home before going to a restaurant.
Though there are now some so-called 'celiac restaurants', they are few and far between, though regular restaurant chefs will also try to accommodate you, if you ask nicely. Instead of trying to give the chef a crash-course in celiac restaurant food preparation, it should be enough to request that your food be prepared in a special manner. And guide them as to the foods they should avoid including in your order while also making sure that you choose items that are more likely to be free of wheat and / or gluten.
For a celiac, restaurant choice should be based on a number of criteria : the type of food generally prepared, the sauces used and the variety of the cuisine available. For example, there is no point going to a pizza joint or an Italian restaurant since most of the items there will contain gluten (except some preparations that use polenta (a kind of boiled cornmeal)). Similarly, for a celiac, Thai restaurants may offer a better choice since the emphasis is more on various types of fish sauces instead of dark soy sauce. But CHECK! some fish sauces may also contain wheat. Similarly, some Cajun recipes call for addition of beer while cooking shellfish which places it out of bounds for a celiac.
Restaurant waiters or waitresses are the celiac's first line of defense against food containing gluten. If they understand the problem, they may be much more cooperative and helpful. Of course, a big tip and a courteous manner helps a lot too. Ask questions without being shy; after all, it's your health that is at stake. Ask whether the fries are coated with bread-crumbs or other gluten-containing seasonings; whether the hamburger patty is pure beef or does it have any fillers and what are those fillers. It is important to understand that it is possible for even the most cooperative waiter to not know that soy sauce contains gluten and the primary responsibility for your health lies with you.