Soak the tamarind and kokum separately for 30 minutes in 1/2 cup water each.
Peel or scrub the potatoes, carrot, okra, eggplants and 2 chillies and cut into chunks.
Heat 4 tablespoons of the oil in a large saucepan and add (in this order) fenugreek seeds, cumin seeds, ginger, chopped chillies and curry leaves.
Fry for a minute, then add asafoetida and gram or wholewheat flour. Stir continuously for 4-5 minutes - the flour will absorb the oil and become a paste.
Lower heat and add chilli powder and turmeric and another tablespoon oil, saute for 2-3 minutes. Add 8 cups hot water, stirring until paste dissolves in the water.
Boil and simmer for 10 minutes.
Add vegetables with salt, sugar, remaining whole chillies, tamarind water, kokum and kokum water.
When vegetables are cooked, add mint and coriander leaves. The curry will thicken slightly on cooking.
Adjust to taste
This delicious, authentic Indian vegetarian curry can be adapted to suit your taste - don't like okra? Then leave it out, or substitute a more preferred vegetable. The chillies are meant to be only a medium heat, so adjust the quantity if you find your fresh chillies are very hot.