1. Fill a bowl with 3/4ths water and add a little salt.
2. Peel the eggplant roughly, chop roughly and add the pieces into the salted water.
3. Peel sweet potato completely, chop into big chunks and add into the water.
4. Chop the tomatoes roughly.
5. Heat oil in a pressure cooker pot or a saucepan to medium heat, add 3 dry red chilies and mustard seeds and remove from the stove.
6. Add turmeric powder and red chili powder, stir and place back on the stove.
7. Add ginger, garlic, green chili, tomato, salt and asafoetida and cook with cover until tomatoes are tender.
8. Add coriander and cumin powder, eggplant and potato and water.
9. Keeping some for garnish add rest of the cilantro leaves and green garlic and stir.
10. Cook with cover till all the vegetables are done.
11. Check for doneness, stir, add water to cook if needed and then stir brown sugar.
12. Remove to a serving plate, garnish with cilantro and green garlic and serve with khichdi.
You can alternately pressure cook this curry up to 2 -3 whistles.