Firstly make the stuffing. Mix together all the ingredients for the stuffing except the flour in a mixing bowl.
Now to make the sauce, heat the oil in a heavy bottomed saucepan until hot and add the mustard seeds.
Just as they begin to pop and crackle add the curry leaves, green chillies, chilli powder, asafoetida, tomatoes, sugar and salt.
Bring to a boil, simmer and reduce the sauce to a thick consistency. Remove from heat and add the chopped coriander.
Cut the aubergines into 2cm rounds and with a sharp knife remove the pulp in the centre, forming a hollow ring.
Toss the aubergine rings with some salt and chilli powder and keep aside in a colander for approximately 20 minutes.
Stuff the aubergine rings tightly with the stuffing mixture.
Now dust these aubergine roundels with the flour on both sides. Shallow-fry the roundels on both sides in hot oil until they form a golden crust.
Serve by spooning some of the tomato sauce on the plate first, top with a few slices of aubergine and then top with a dollop of yoghurt with garlic and mint and juliennes of ginger.