Recipe from my nani (maternal grandmother) Mrs. Premlata Sinha.
Wash, pat dry, and cube the mangoes; do not peel.
In a pan over low heat, dry roast the pachphoran (the mix of five seeds) until fragrant. This may take 3-5 minutes. Allow the seeds to cool down.
Place the cubes of mangoes in a deep mixing bowl and add the oil, chilli powder, turmeric, and coarsely chopped chillies. Pound the seeds to a coarse powder and add to the mango-spice mix. Mix well.
Cover this bowl with a piece of muslin and let this sit under the sun for 3-4 days. Once the achaar is ready, transfer it into a glass or ceramic jar and store in a moisture-free area at room temperature.
Room temperature, airtight jars
* Pachphoran: ⅓ tsp each of ajwain (carom/caraway seeds), mangrela (onion seeds), saunf (fennel seeds), methi dana (fenugreek seeds), and rai (black mustard seeds).
Remember to bring it back after the sun sets else it will get spoilt with the dew.
Use a clean dry spoon for serving the achaar.