Spread the mango pieces on a clean kitchen towel and let them dry for 3-4 hours.
Heat oil in a pan until it is very hot.
Remove the pan from heat and let the oil cool completely.
Dry roast fenugreek seeds until slightly browned.
Add fenugreek seeds and mustard seeds in a blender and blend to make a smooth powder.
Add mango, fenugreek and mustard powder, red chilli powder, turmeric powder, salt and garlic pods in a bowl.
Now add half of the cooled oil and mix well.
Transfer the pickle in a clean glass jar.
Top with the remaining oil.
Cover the jar with a lid or tie with a muslin cloth.
Keep the jar in strong sun for 3-4 days.
The pickle is ready to use now.
Top the jar with more oil to make sure mangoes are covered with oil.
Notes
Use sour raw mango to make this mango pickle. They are the best when the season just starts for Mangoes that is in May June.Cut them into even pieces. You can also get them cut from the vendors who have cutting machines. They sit all over the local vegetable market in India.Make sure to cover the pickle with oil at all times. It will ensure it doesn't go bad.This Andhra style pickle uses Sesame Oil. Replacing it with any other oil will not give the same flavour.Always use a clean dry glass jar to store the pickle. A plastic one will leave a smell in the pickle which will be very non appetising.