The Simple Life outlet in the KLCC food court is one of the few places there that offer some vegan options.
Be sure to check what they have to offer - I have sometimes received information in other outlets of the chain that were not completely consistent - e.g. "The curry should be vegan, but sometimes they use dairy milk". So make sure to ask in the restaurant that you go to which of their options really are vegan.
Their Nasi Lemak (order WITHOUT EGG, because traditionally, Nasi Lemak also has a half hard-boiled egg), however, is quite nice, and they do offer some other vegan sets.
Prices are ok for the location, though not exactly very cheap.Pros: Tasty food, Many vegan options, but make sure to ask, OK prices