Wash and wipe-dry the apple.
Cut it horizontally into half inch long slices.
Add sugar, vinegar, salt, turmeric, chilli, cumin, coriander and mustard powder. Keep aside.
To prepare tempering, heat oil in a wok and fry mustard and cumin seeds.
Add nigella seeds and fenugreek seeds.
Add ginger and garlic paste and after a few seconds, remove from heat and let it cool.
Pour the mixture over the apple.
Transfer it to a clean, dry airtight bottle.
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