If Popeye were Indonesian, to get his incredible strength he won't eat spinach (bayam), but kangkung. Kangkung is the Indonesian water spinach, with hollow and crunchy stems. It is also popular in other parts of Southeast Asia. In Mandarin it is called Kong Xin Cai, meaning the veggie with hollow center, referring to the stem. In Cantonese it is called on-choy. The word "to stir fry" in Indonesian is "ca" (borrowed from Chinese, and is pronounced like cha in cha-cha), and it is also the noun (the stir fried dish).
In Indonesia, we "ca" kangkung with garlic, chili, palm sugar (gula Jawa), and add a touch of terasi for that natural umami taste.
You can get kangkung from your local Chinese grocery. Otherwise, use regular spinach and cook it like you would kangkung. Voila!
Terasi or Terasi Bakar
For more creative recipes of kangkung, including Plecing Kangkung, we found this food blog.