Roughly chop amaranth stems and keep aside.
Roughly chop onions, green chillies and ginger and place in a mixer jar. Add garlic cloves, tomato and half the amaranth leaves. Add little water and grind into a paste.
Heat oil in a non-stick pan, add the ground masala and sauté for 5-7 minutes.
Grind the remaining amaranth leaves with a little water and set aside.
Add coriander powder, red chilli powder, dried mango powder and salt to the pan and mix well.
Add turmeric powder, mix well and sauté for 2 minutes. Add the stems and the second ground paste. Mix well and cook for 20-25 minutes or till the stems are completely cooked.
Transfer into a serving bowl and serve hot.