That sounds like India.The only way I've seen it cooked over here is people take a moringa (the whole drumstick – the fruit, the part that has the seeds) not the leaves though, and they slow cook it in what they call a white curry, though everything is called a curry here so I'm not sure if that's the most accurate way to describe it. I don't know off the top of my head what actually goes into it, apart from coconut milk and salt. It's a very light colored dish, almost white, slightly yellow.
I'll try to take a picture of it next time I see it, and inquire about the full list of ingredients. It's eaten with rice + other curries. Never on it's own.