Cut each lemon into 4 pieces. Add salt and turmeric powder. Mix well and allow to settle for ten minutes.
Take 2 cups of water in a thick and deep bottomed vessel and boil. Add the marinated lemon pieces and cook on a low flame until the lemon pieces become soft and well cooked. Keep aside.
Take the fresh red chillies into a grinding jar and prepare a smooth paste.
Add oil to a frying pan and heat. Add the cooked lemon pieces, red chilly paste, fenugreek powder, cumin powder, tamarind paste and jaggery. Mix well and allow to simmer in low flame till all the ingredients blend with each other and the oil shows up.
Take another frying pan, add four spoons of oil and heat. Splutter the mustard seeds, add asafoetida and the red chillies and saute. Add this to the above and mix well.
Save in a dry jar or glass bottle. Good after one day.