Wash, peel and grate fresh turmeric. Set aside to dry. I usually do this in the night and keep it covered in a colander overnight so that all the water is drained.
Heat oil in a small pan and add heeng. Add mustard seeds, methi seeds and fry for 2 minutes till lightly brown and fraganant. Add dry spices and fry for another 1 minute.
Take off the heat and pour over the grated turmeric. Add chopped green chillies, lemon juice and mix well.
Pour in glass jars. The pickle remains fine for a month in fridge.