Kathal ka achar

Step 1: Rub 1 tbsp neutral oil over your knife, board and hands. Cut away the thick green skin and the central white core of the 2 ¼ lb raw green jackfruit, then cut the flesh into 2–3 cm chunks.

Step 2: Bring 2 litres of water to the boil with 1 tbsp salt and ½ tsp ground turmeric, add the chunks and boil over a medium-high heat for 8–10 minutes, until a knife slides in with slight resistance at the centre.

Step 3: Drain, spread on a clean cloth and leave for 3–4 hours (or 1 hour under a fan), turning once, until the surfaces feel dry to the touch.

Step 4: Clean the jar and lid: wash in hot soapy water, rinse, then dry in a 250°F oven for 10 minutes (or boil for 10 minutes and air-dry upside down on a rack). Let it cool completely; jar, lid, bowl and spoons must be bone dry.

Step 5: Dry-roast 3 tbsp fennel seeds (saunf) and 1 tsp fenugreek seeds (methi dana) in a pan over a low heat for 2 minutes until fragrant. Cool and crush coarsely with 2 tbsp yellow mustard seeds, then mix in 1 tsp nigella seeds (kalonji).

Step 6: Heat 1 cup mustard oil until it smokes and lightens to pale gold, about 3 minutes, then turn off the heat and cool until warm.

Step 7: Combine the crushed spices with 1 ½ tbsp red chilli powder, 1 tsp ground turmeric, 1 tbsp dry mango powder (amchur), ¼ tsp gluten-free asafoetida and ⅞ oz salt. Stir in 4 tbsp of the warm oil, then the ¼ cup white vinegar, and toss the jackfruit in it until evenly red.

Step 8: Pack into the jar and pour over the rest of the oil when cold, so the chunks are covered by 2 cm. Close and refrigerate.

Step 9: Shake the jar once a day. After 3 days it is ready: the chunks are tawny through and taste sour and spicy to the centre. Keep in the fridge up to 1 month, always under oil, dry spoon each time; discard if you see mould, fizzing, sliminess or smell anything off.