Green chilli in mustard sauce is a delicios pickle if you like real hot taste.
But generally we do not preserve it, we make fresh for cooking or preparing sauce. I dont know the appropriate
used for it. So dont preserve it.
I am posting the recipe here:
for 4 peoples
Take a spoonful black mustard seed.
Soak in water for 5 min
grind the seeds with a pinch of salt with Indian stone grinder (sil nora)
chopped 4 green chilli and mixed in the mustard sauce with a spoon (dont touch it with fingers otherwise you will feel burning sensation in your fingers because it is extremely hot)
At last I want to tell you 2 facts about this recipe:
1. If you grind the mustard seeds with electric grinder you will not get the real taste.
2. If you cannot grind the seeds properly it will become bitter in taste.