Wash tomato and cut it in small pieces
Add tomatoes in cooker whistle it
Now turn of gas
When tomatoes turn little warm grind it
Sieve grinded tomato add sugar,citric acid and salt
Boil this puree about 30 min
When puree turn thick take a drop of puree on plate
Check it when a water ring show in puree means it not done
Again cook some time now turn off gas
When puree turn little warm take little quantity of puree in bowl
Add sodium benzoate mix it now add this mixture in puree mix it
Store this puree in jar keep it in fridge for long time
