Steam the potatoes in their skins until fork tender, then drain and allow to cool. Peel once they are cool enough to touch, then cut into 2-inch/5-cm pieces.
Remove the stem end of the eggplant and quarter it lengthwise. Cut the stem end into 2-inch/5-cm pieces. Cut the four part of the bottom end in half again and cut into 2-inch/5-cm pieces. Soak the pieces in a medium bowl filled with cold water for about 30 minutes, then drain well.
Heat the oil in a large saucepan over medium heat. Add the coriander seeds and cook until they begin to release their fragrance, about 3 minutes. Add the onions, ginger, and peppers and cook, stirring occasionally, until the mixture begins to brown, about 7 minutes.
Add the curry powder and stir, cooking for 1 minute, then add the tomato paste and stir. Add the warm water, salt, and chickpeas, and eggplant, then bring to a boil. Reduce heat to medium and cook for 8 to 10 minutes, stirring occasionally. Add the potatoes and cook another 2 to 3 minutes.
Ladle into bowls with brown rice and garnish with cilantro leaves, or serve with pieces of Indian flatbread.