Return pan to medium heat and heat ghee or oil until shimmering. Add the mustard seeds and split black gram, stir until they splutter, about 30 seconds. Add the onion, nd Kaaju fry until slightly soft, about a minute (take care not to brown). Add the slit chillis, curry leaves and stir until fragrant, about a minute longer. Add the carrots, peas, red chilli powder, and sugar, and stir until fragrant and the mixture is coated with the ghee/oil, about 1 minute