Now that most of Japan is in the midst of a hot, sweltering summer, it's a good time to take a look at the traditional cuisine of a part of the country that lives with warm weather throughout the year: Okinawa.

Okinawans are renowned worldwide for their longevity, and while a healthy, easygoing lifestyle may have as much to do with that as anything else, their traditional cuisine may contribute to it too. It features lots of fresh, local land and sea vegetables, tofu and seafood, together with pork (the consumption of which has increased substantially since the end of World War II).

The most famous Okinawan dish is probably gōyā champurū. It's a humble stir-fry of tofu, egg, pork and an odd-looking vegetable called gōyā in the Okinawan language, nigauri or tsuru reishi in Japanese and bitter gourd or bitter melon in English. Bitter gourd is a subtropical plant that's grown throughout the subtropical parts of Asia; in Japan, it's primarily grown in the southern parts of the country including Okinawa. While it's available year-round these days, like other plants in the cucurbitaceae family, such as cucumbers and squash, its true season is summer to fall.