Soak the mustard seeds in water for at least 10 minutes.
Then transfer the mustard seeds into a blender and blend into a smooth paste.
Heat oil in a pan. Add the nigella seeds. Saute.
Next, add in the red chilies and saute.
Add the mustard paste next and mix well. Saute and cook for 2-3 minutes.
Add the salt and vinegar and mix well.
Let the pickle cool down.
Once it’s cool enough, transfer it to a glass tumbler and store air-tight.
Enjoy with Indian delicacies.