Karonde ka achar

Step 1: Wash the 1 ⅛ lb karonda berries and 8 fat green chillies and dry them thoroughly. Halve the berries and flick out the seeds with the tip of a knife (cranberries just need halving).

Step 2: Toss with 1 ½ tbsp salt and 1 tsp ground turmeric in a dry bowl and leave for 2 hours. Pour off any juice, then spread on a clean cloth in sun or a warm airy room for about a day, until the cut faces look dry and slightly wrinkled.

Step 3: 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 4: Dry-roast 2 tbsp fennel seeds (saunf) and 1 tsp fenugreek seeds (methi dana) in a pan over a low heat for about 2 minutes, until fragrant and a shade darker. Cool, then crush coarsely with 2 tbsp yellow mustard seeds in a mortar and stir in 1 tsp nigella seeds (kalonji).

Step 5: Heat ¾ cup mustard oil in a pan over a high heat until it smokes and the colour lightens from deep yellow to pale gold, about 3 minutes. Turn off the heat and let it cool until just warm.

Step 6: Mix the crushed spices with 1 tbsp red chilli powder, ¼ tsp gluten-free asafoetida and 1 tbsp salt, moisten with 3 tbsp of the warm oil, then add the dried fruit and chillies and the 2 tbsp lemon juice. Toss until every piece is coated.

Step 7: Pack into the jar, pressing down, and pour in the rest of the oil when cold so it covers the fruit by 2 cm. Close and refrigerate.

Step 8: Shake the jar daily for 7 days. It is ready when the berries are tender and the masala smells mellow rather than raw. Keep in the fridge up to 2 months, fruit under oil, dry spoon each time; discard if mould, fizzing, a slimy texture or a rotten smell appears.