Wash the green mango (Kairi) with water. Clean each piece nicely with a kitchen towel. Peel the skin of the mangoes using a knife or vegetable peeler. Now dice the pulp into equal size pieces. Discard the stone.
Mix diced mangoes, salt, and turmeric in a large tray or bowl. Cover and keep aside for 2 – 3 hours for mangoes to release water/juices.
Once the fruit’s water is released, transfer the mangoes to a colander to drain all the water.
Combine turmeric-coated mangoes, green chili, homemade pickle masala, red chili powder, asafoetida, salt, mustard oil, and white vinegar. Mix them nicely to coat each piece of green mango with spices and oil. Use your hands for the purpose.
Taste and add more salt/red chili if required. Transfer the mango pickle to a clean, sterilized, dry jar. Cover the opening of the jar with a piece of muslin cloth. Seal it with a lid.
Now the pickle is ready to consume. You can serve it immediately.
Store instant mango pickle in a clean, dry jar at room temperature. Shake it once every day so that the top layer gets evenly coated by oil and masala sitting at the bottom of the jar.