Allow it to cool and Remove the skin and grind well in a mixer. Pour that mixture in a kadai and boil it
Boil till the puree doesnÆt stick to the sides of the vessels and changes to dark color and the water evaporates.
When such consistency is reached, add salt, sugar and vinegar and boil well. When sugar is added it melts and leaves the mixture in liquid form. Stir it occasionally so that it doesnÆt burn until the sauce consistency is reached
Collect it in bowl and serve. This sauce can be used as replacement for the ketchups thatÆs bought in store.