Clean and soak tamarind in 1 cup hot water. Take care to remove any seeds that may be in tamarind. Boil in same water after 20 minutes. Cool and blend in mixie till smooth. Add remaining water, mix well. Pass through a sieve, removing any fibres, etc. Heat oil in deep heavy pan. Add tamarind paste, bring to a boil. Add salt, cook till a thick coating consistency is got. Cool completely, stirring in between, fill into clean sterile jar.