When I was in college I did my junior semester abroad in Thessaloniki, Greece. One of things I miss most is getting a homemade Gyro off the streets for .50 or so. They were delicious. My friends and I had our favorite Gyro place we would go to. We actually got really addicted to them and were there so much the owner would wave to us whenever we walked by his shop.
I'll never forget on my return home making the mistake of ordering one at Applebees or somewhere similar. I should have known that I was in trouble when they pronounced it American style: Guy-row instead of the proper Greek way that sounds kind of like this; Yearow. It was the most horrible thing I've ever had and I learned a good lesson: never order International Cuisine from a chain restaurant unless it's been years since you've been out of the country! I also miss tzatziki sauce and living close enough to water to get fresh seafood. It's the only time I ever had Octopus and liked it!
When I was in the Peace Corps I lived in Morocco, and what I miss most from there is homemade Couscous When I came back and saw Near Easts' Sun Dried Tomato Couscous I laughed so hard and no one understood why. I also miss eating Tangine and so many other wonderful dishes.
I could go on and on about other international food I miss, but it's a little depressing as I haven't left the country in 10 years. I miss the days when I could travel and not have to worry about finances.