There are four types of fruit or vegetable that I was introduced to in Guatemala: Lychee, Zapote, Guisquil, and Pitaya. Because I learned of them in Guatemala, I know them by their Guatemalan names; with the exception of lychee... I'm not sure what it's called in Spanish since a fellow expat introduced it to me. So let's start with that one:
Lychee: a colorful, reddish fruit on the outside with a grape-like inside surrounding a seed, is quite sweet! You just peel off the red part, eat the white and spit out the seed. I think the flavor is similar to that of a grape as well.
Zapote: From the outside, I think this looks like a sweet potato or tuber but it is actually considered a fruit. It has thick brown skin on the outside with an orange flesh surrounding a large dark brown seed. I wasn't impressed with the mild, slightly sweet flavor, but I figure it's something one must develop a taste for. (Image from A.M. Costa Rica)
Guisquil: Known in English as "chayote," this light green squash-like vegetable has a white meat and an interesting juice. When we cut it, if it got on our hands it made them feel like the skin was drawn up very tight, like something you'd expect a fancy spa to put on your face to make you look younger. ;) (If you try that, let me know if it works. That'd be a great natural alternative to Botox for interested people!) In Guatemala we would peel, cut into large round slices and boil the guisquil. Then, we would coat it in the same egg mixture used to make envueltos de ejote, (green bean wraps) and fry in olive oil. It was very tasty this way or boiled like any vegetable in a soup or stew.
Pitaya: Known as "dragon fruit" in English, what points this exotic fruit gains in appearance, it loses in flavor. It's bright magenta skin with green-spiked leaves are peeled away to expose a white or magenta flesh filled with little black seeds. The flavor is not sweet, and reminds me of a raw potato. It is sometimes made into chips or cut up raw and added to other fruit mixtures or covered with sugar to give it some flavor. There should be a proverb about the pitaya... something like, "Though it looks as exciting as a pitaya, it is as flavorless." (Maybe you can come up with a better one. ;))
Have you tried any of these fruits or vegetables? Did you like them? Where were you introduced to them?