I am guessing this means - the food is from outside the country you are in now. I would never say this, I would probably use the word 'foreign' or more than likely specify the country of origin. Would use international only if it was a lot of food from many different countries. Phew!
I just assumed it meant "fusion cuisine", which is indeed food from many different countries -- often techniques or spices from various countries combined into one dish, or served in a complementary fashion.
Heck, it happens in my own kitchen, though in a less sophisticated way. We got the German, the Sicilian, the Florentine, the plain old New Englander, we've got Mrs Chiang's cookbook, all the condiments and spices to go with, and we're not keeping them carefully separate, either.
If you have no noun after it, "the" makes no sense, so it's "that":
Das ist gut = That is good. (The is good makes no sense)
If you have a noun after it, it's best to assume it's the article, at least in writing:
Das Essen ist gut = The food is good
There is nothing that indicates that "das" is supposed to be a demonstrative here. If you hear the sentence, and someone means "that food", he would stress the "das" very, very strongly. But unless someone tries to emulate the stress by typing
Das Essen ist gut
you would just read it as an article. Because of that, you would rather use
Dieses Essen ist gut
in writing to make the difference clear.
Why do you think Iranian Kebab is an international food? you find roasted beef in many countries in various shapes from Turkey to USA. some variants even have the name of "Kebab". but the truth is that the name and least of all the food is not recognized as Iranian cousine anywhere in the world. Even "Kale Pache" is not universally regocgnized as an Iranian cousine. there is no such think as international food.