Make sure the mangoes are sour. Peel and cut mangoes into small pieces. Fry menthulu(fenugreek), mustard seeds and red chillies without oil till the mustard seeds splutter. Cool and grind into a smooth powder. Add this powder, salt, turmeric and jaggery to the raw mango pieces and mix well. Heat a little bit of oil. Add inguva(hing / asafoetida) to it and mix this oil with the mango pickle. It is ready to eat.