Thoroughly wash and dry the lemons. Cut each one in half, through the middle, then cut each half into quarters, so you end up with eight half wedges from each lemon. Remove the seeds.
Place lemons in a bowl and sprinkle with salt. Toss to coat each wedge evenly.
Firmly pack the lemon into a sterilised pickling jar and store in a sunny place for two weeks. Stir every two days using a sterilised spoon. This process will soften the skin on lemons.
for the syrup
When the lemons are ready, prepare the syrup by placing the jaggery with one cup of water in a pan, bring to a gentle boil, then reduce the heat to low and simmer for 15 minutes or until syrup thickens to a consistency of cream.
While the jaggery is simmering, remove the seeds from the cardamom pods and coarsely crush. Set aside.
Once the jaggery syrup has thickened, add the chilli powder, garam masala, black salt, ginger powder and the reserved crushed cardamom. Mix well.
Remove the lemons from the pickling jar and discard the liquid. Add the lemons to the syrup and mix gently.
Return pan to a very gentle simmer, and cook for further ten minutes, or until the pickle thickens noticeably. Mix frequently.
Once thickened, remove from heat and allow to cool completely. The pickle will thicken more as it cools.
Once cool, transfer to a sterilised jar, seal and store in a cool, dark place until ready to serve.
notes
Choose small, thin skinned lemons for the best result.
Discard the pickling liquid - it is very salty and will overpower the taste of the pickle.
Black salt is available from good Indian grocers or spice merchants.
This recipe takes at least two weeks from start to finish, minimum.
This pickle keeps good for up to a year if unopened, and stored in a cool dark place. Once opened it should be refrigerated and used within a week.
Always remove pickle from the jar to serve. Remove enough to serve and place into a serving bowl.