Prep & Soften: Mix clean, dry raw Kabuli chana with diced raw mangoes, turmeric powder, and salt in a dry bowl. Cover with a cloth and let rest for 24–36 hours, stirring twice daily, so the chickpeas absorb the sour mango juice.
Smoke the Oil: Heat mustard oil to its smoking point in a pan, then turn off the heat and cool completely to room temperature.
Roast & Grind Spices: Lightly dry-roast fennel, yellow mustard, and fenugreek seeds until aromatic. Coarsely crush them using a mortar and pestle or grinder.
Mix the Pickle: Add the ground spices, whole kalonji, crushed ajwain, Kashmiri red chilli powder, and hing to the mango-chana mixture. Pour in the cooled mustard oil and mix thoroughly.
Sun-Cure & Store: Transfer to a clean, dry glass jar. Place in direct sunlight for 5 to 7 days, shaking gently once daily until the chickpeas are soft with a crisp bite.