Shikarpuri achar

Step 1: Sterilise the jar and lid: wash in hot soapy water, rinse, then set the jar upside down in a 250°F oven for 10 minutes (or boil jar and lid for 10 minutes). Let it cool and dry completely; jar, lid and every spoon you use must be bone dry. Use a 2 litre jar or two 1 litre jars.

Step 2: Drain the soaked 3 ½ oz dried white chickpeas and spread them on a cloth in the sun or a 122°F oven until the surface is completely dry, about 2 hours (or overnight indoors).

Step 3: Wash the 1 ⅓ lb raw green mangoes, 6 limes and 9 oz carrots and dry them thoroughly with a cloth. Cut the mango, with skin and with the soft inner stone removed, into 2 cm pieces; quarter the limes and pick out the seeds; cut the carrots into 4 cm batons.

Step 4: Toss all the vegetables and the chickpeas with the 3 ½ oz salt and 2 tsp ground turmeric in a large dry bowl. Spread on a tray, cover with muslin and dry in strong sun for a day (or in a 122°F oven for 3–4 hours) until the surfaces look leathery and no liquid pools.

Step 5: Heat the 2 cups mustard oil in a heavy pan over a medium-high heat until it just begins to smoke, about 5 minutes, then turn off the heat and let it cool completely.

Step 6: Mix the 3 tbsp fennel seeds, 2 tbsp fenugreek seeds, 1 tbsp nigella seeds, 2 tbsp yellow mustard seeds and 3 tbsp red chilli powder in a dry bowl, then stir in the ½ cup white vinegar and 100 ml of the cooled oil to make a thick paste.

Step 7: Coat the vegetables thoroughly with the masala paste and pack them tightly into the sterilised jar.

Step 8: Pour over the rest of the cooled oil until everything is covered by at least 2 cm. Tie muslin over the mouth and set the jar in the sun (or a warm spot) for 2–3 weeks, shaking it gently once a day; add more heated and cooled oil if the level drops. It is ready when the lime rind is soft.

Step 9: Close with the lid and keep in a cool, dark cupboard for up to a year, or in the fridge in hot, humid weather. Always use a clean, dry spoon and keep the pieces under oil. Throw it away if you see fuzzy mould, if it fizzes or the lid bulges, or if it smells rotten rather than sour and spicy.