In a large saucepan, heat the oil and add the onion, ginger and garlic. Cook until softened. Add the curry paste and lemon grass. Pour in one cup of coconut milk, lime leaves, fish sauce and sugar. Bring the sauce to a boil and add the cauliflower. Stir well and cook for 5 minutes. Reduce the heat to a simmer and add the eggplants, long beans, chili and remaining cup of coconut milk.
The mixture is done when the eggplant it cooked through yet retains its firmness. Season to taste and add cilantro leaves, retaining a few for garnish.
Note: As this curry is intended to be quite hot, it is suggested that the seeds in the chilies NOT be discarded. However, this decision depends solely on personal tastes, as does the variation, up or down, of the number of chilies used. *Can be obtained at: Asia Market, 71 Mulberry Street, NYC, Attn: Cathy, telephone: (212) 962-2028