Wash the amaranth leaves a couple of times in running water in order to remove any dirt or grit. Drain, cut off any of the tough bottom parts of the stalk and discard (if using swiss chard, chop finely the larger part of the stalks). Roughly chop the trimmed greens into bite sized pieces.

Heat the oil in a sauté pan over medium high heat. Add the sliced onion and cook for 2 minutes. Reduce the heat to medium and cook until the onions are soft and golden, about 5 minutes. Add the chopped garlic and green chillies to the pan and continue to cook for another 2 minutes. Toss in the chopped amaranth and a pinch of turmeric. Mix well, cover and cook for about 4 minutes until the leaves are wilted and tender. If using spinach, the cooking time will most likely be halved. Remove the lid and continue to cook in order to allow any excess moisture to evaporate. Add the grated coconut, salt to taste, and sauté for another minute. Serve immediately.