Heat oil in a pan and add mustard seeds and when they crackle add red chilly and curry leaves and fry for a while. Add the green chilly and fry till browned. Now add tamarind paste turmeric powder and salt and bring to boil. Now reduce the heat and cook on low flame. Meanwhile, heat a pan and roast fenugreek seeds and rice till browned and grind to get a fine powder. Add this to curry. Continue cooking on low flame till gravy is thickened. Remove from flame. Serve this as a pickle. It can be kept refrigerated for a month.