I do not understand how wordpress processes search requests nor how the category and tag labels are used. The Greek tags don’t seem to work at all and even if you make a search request using a keyword that matches a tag, there’s no guarantee you’ll be able to retrieve that recipe. So, you ask, why keep making the Greek and Greeklish tags? Well, they work well for the search engines. Search for `tourta sokolata’ for example or `manitarisoupa’ or `syntages me loukoumia’ and see what you get 
My best advice is to use a) the name a basic ingredient, b) dish names if you remember them, c) category tags (dinner, dessert, etc) and only as a last resort what you’d think would be a tag. And, then, again never assume that the search results are accurate. More often than not there’s a recipe that matches your keyword that will not show up. If you have figured how tags work in WordPress, let me know. Good luck!
Last updated 3/1/10
