Heat the olive oil in a medium saucepan. Add the cumin seeds, cinnamon stick, and cardamom pods and cook over moderate heat, stirring often, until the cumin is browned, about 1 minute. Add the rice and vegetable stock, cover and bring to a boil. Reduce the heat to low and simmer, covered, until all the liquid is absorbed and the rice is tender, about 15 minutes. Add the corn, cover and cook until heated through, about 2 more minutes. Season with salt, fluff with a fork and serve.