Make a slit into eggplants, but not cutting them into half. If you are using Japanese eggplant slice them in 8 long pieces.
Heat the oil in flat frying pan over low medium heat and stir-fry eggplant rotating occasionally till they are tender not mushy. Set them aside.
For the spice mix take all the ingredients, cumin seeds, fenugreek seeds, coriander seeds, cashews, sesame seeds, and coconut powder, and grind them in fine powder. Set it aside.
Blend tomatoes and ginger together to make into fine puree. Set it aside.
Heat the flat frying pan over low medium heat, I am using the same pan I stir fry the eggplants. When the oil is moderately hot add the mustard seeds as they crack turn off the heat. Add all the spices asafetida, turmeric, red chili powder and dry spice mix stir for about 2 minutes, all the spices should be roasted.
Add tomato puree, sugar, salt, and about 1 tablespoon of tamarind paste. Stir fry the gravy until the mix becomes a little thick and start leaving the oil from the sides. Add 1/2 cup of water and bring it to a boil.
Add the eggplant spreading in the frying pan, stir gently cover the pan lower the heat to low and let it simmer for about 7-8 minutes stirring occasionally.
Eggplant should be soft and tender not mushy and coated well with the spices. Adjust the gravy thickness to your choice. Add the cilantro stir gently.