Cut the mangoes into small size and marinate them with salt.
In a grinder, powder the mustard seeds.
In a deep pan, heat gingelly oil and add curry leaves and mustard powder.
Add garlic, ginger and green chilly to this.
Sauté for a minute and then add Mangoes, followed by Chilly powder and Pickle powder.
Combine well, and do adjust the salt. Add oil if its too dry.
Put off the flame and add vinegar to this.
Transfer the contents to a dry glass bottle, when completely cooled.
Make sure that there is no water involved during the whole process.
You can use it from the same day on wards but better wait for 2-3 days for the flavors to get infused.