Halved your scrubbed lemons and juice them most of the way. Save the juice for another use
Cut each half into six pieces or slim slivers
Layer the lemon pieces into the bottom of the jar, press them down enough to create an approximate 1.5-2 inch layer
Add your add ins of choice (or none at all) and sprinkle with 3/4 tbsp pickling salt
Repeat until the jar is filled to the top
Shut the lid tightly and leave in the sun for 10 days. The lemon rind will change colour, the salt will leach some liquid out of the lemon, this is all normal (and good!).
Invert the jars every day to distribute the natural pickling liquid. Check on it after 10 days, the rind should be nice and soft, if not then leave out for another few days
Eat with daal chawal, khichri, biryani, matar pulao.
More fun stuff: once your lemons are beautifully tender you can always doctor small amounts to suit your mood. For example you can mix in a little brown sugar and chilli flakes or simply add a little chaat masala over top.