We have lot to do while we travel across the place or country. We need to know about the remote place and need to have some local currency. Hence we have tag to define each of these to help people by stating them as foreign.
foreign exchange - Place where you can get currency.
foreign policy - Place where you can collect information.
foreign national - Place where you can update your citizen status.
foreign language - Place where you can know about the language.
foreign corporation - Place where you can have an account.
foreign affairs - Place where you can know the news.
But when we travel outside the dwelling place do we have anything that describes about the food that is practised. It is sometimes very difficult to visit a foreigner to a country where he is likely to find any vegetarian food.
why don't we have,
foreign food - Place where you can have food.
I agree that restaurants are categorized based on continental operation. This will not solve you to have all the food that you taste at your dwelling place. It serves only what they supply.
"Foreign food" is something like you got your cook next to you to serve what you tell and he understands to prepare it best way that you daily taste.
I relate it to the movies like "chini cum" or "ratatouille", place where things are cooked to touch the heart of the consumer, still it is about the food that restaurant supply but not the one cooked at the spot as asked by the consumer.
