Wash and dry the limes (or lemons). Chop them into wedges, and deseed them as far as possible.
Apply salt to the chopped limes and sundry them for a couple of days.
Roast the fenugreek seeds and cumin seeds. Cool them before grinding (next step).
Grind the two types of roasted seeds together with red chillies (or chilli powder), turmeric/saffron, ginger and garlic in vinegar only.
Next, heat some oil in a deep non-stick pot.
Fry the ground masala paste on low-medium heat for 5-8 minutes.
Add the sugar and 1 cup vinegar. More sugar may be added if the limes are too sour. Fry for a further 5 minutes.
Then add the sun-dried lemon wedges, draining off excess water. Add salt (if required).
Cook for another 20 minutes or longer if the limes are thick-skinned on medium heat. Stir occasionally to avoid sticking to the bottom of the pan.
Cool and empty into sterilised glass jars.