In a 12-inch skillet over medium-high, heat the oil until barely smoking. Add the pork, curry powder, 1½ teaspoons salt and ½ teaspoon pepper. Cook, stirring once or twice, until the pork is well browned, about 4 minutes. Add the onion, ginger and cardamom; cook, stirring, until the onion is browned, about 2 minutes. Add the beans and 1½ cups water; bring to a simmer, scraping up any browned bits. Cover partially and cook, stirring occasionally, until the beans are tender and the sauce clings to the meat, about 15 minutes. Remove and discard the cardamom, then taste and season with salt and pepper.