Peel the ginger, Chop fine and keep aside. Chop the green chillies fine and keep aside. Soak the tamarind in a little water and keep aside. Roast that is heat without oil, the fenugreek seeds until they turn dark brown; grind into a fine powder and keep aside. Squeeze out the tamarind, retaining the water solution, sieve the solution and dilute it with 200 ml of water and keep aside. Saute ginger and green chillies with turmeric powder in a little oil and keep aside. Heat oil in a sauce pan and add mustard. When the mustard crackles, add tamarind and water solution and salt to taste and simmer the ingredients. When the ingredients have boiled down to 1/4th of the original volume add ginger and green chillies, powdered fenugreek seeds, asafotida and jaggery to taste and stir well.