Boil the chembu pieces with little salt and turmeric powder. Do not over cook.
Heat oil in a wok / Meenchatti. Add mustard seeds,let it splutter. Add fenugreek seeds and toss.
Add sliced onions,crushed ginger ,garlic and shallots,curry leaves , green chillies and little salt and saute till onions turn light brown.
Add turmeric powder and red chilli powder and mix well till oil separates.
Add a cup of hot water,cover and cook for 5 mins.
Add kudampuli/ pot tamarind when it starts boiling.
Add boiled chembu pieces and some more water and cover and cook for another 10 mins. Add salt if required.
Switch off the flame when done and keep it covered for some time before serving.
