Sun-dry chillies and mustard seeds for one last time. Sterilize all spoons and Barnis in boiling water and let it dry completely.
Strain brined liquid from the jar into a pot. Add 1.5 cups of water. Mix and bring it to a rolling boil. Cool completely.
Grind all masala ingredients using only the boiled brined water.
Scoop out the ground paste into strained mango pieces. Mix well and taste test. More Hing and Salt can be added at this stage if required as per taste. Done.
As long as you keep wet spoons or any moisture at bay it stays well outside. We refrigerate the pickle after a month or so.
Optional step to increase shelf life is to add a tiny piece of cloth soaked in a tsp of coconut oil and hing on top of the jar or barni before putting the lid.