Mix well, and add the turmeric and chilli powders and stir well. Add the salt and 1/2 tbsp powdered jaggery. Add a little more jaggery if you feel your Thokku is a little too tangy. Mix well and let it come to a boil. Turn down the heat to medium and let the mixture cook down until most of the liquid has evaporated and the oil surfaces. Add the fenugreek powder, mix and let the Thokku cook for another couple of minutes.