In a pan / kadai.. preparing tempering. Add oil and splutter mustard. Later add hing and curry leaves.
Add shallots, salt and haldi. Saute well for 4-5 mins .
Mean while prepare masala. In a kadai add few drops of oil. Add all the ingredients mentioned under "masala to grind". Fry till crisp. Allow to cool and grind it smooth adding little water .
Saute onions till it's translucent and soft.
Add tamarind pulp, salt, jaggery and ground masala. Mix and add water as required. It will be tangy, spicy with a hint of sweetness.
Simmer on low flame and boil well.
Tangy spicy Ulli Theeyal is ready. Relish it with rice.