Cut the eggplant into thick batons, Place the eggplant on a strainer, season it with salt and turmeric and leave aside for 30 minutes, until water comes out of the eggplant
Peel the shallots, slit the green chillies in the middle or cut them in an angle lengthwise
Grind the mustard seeds in a mortar pestle until it resembles mustard powder, add vinegar and salt and leave aside for 30 minutes. Leaving this for 30 minutes will ensure the bitterness of the mustard seeds is evaporated Heat a pot of oil on medium heat and fry the eggplant in batches until golden and cook through. ( dry the eggplants on tissue paper prior to frying) Fry the shallots and green chillies at the end. Just flash fry for 30 seconds until par-cooked. Let the fried eggplant, shallots and green chilli drain on a paper towel until needed Once the mustard mixture is kept for 30 minutes, add chilli powder and pour the whole mixture into a pot or preferably into a clay pot, and leave it on a medium fire. Add the tamarind juice ( not the seeds), ginger garlic paste and white sugar into the same mixture and let the pickle gravy come to a boil. Let the mixture reduce and thicken on a low fire for about 5 minutes.At this time, taste the mixture and see if the flavours are well balanced.To make tamarind essence, place the tamarind seeds with 1/4 cup of water and massage them and leave aside for 10 minutes. After 10 minutes you will see the water has become tamarind juice/essence Once the gravy has come to its correct consistency, add the fried eggplant, shallots and chillies, mix through until all the eggplants have absorbed the pickle gravy. Turn off the fire.
Serve with hot hot rice and accompaniments of your choice