How to Make It
Bring a large pot of water to a boil and salt the water. Add the kale leaves and cook until tender, about 6 minutes. Drain and let cool, then coarsely chop.
In a large pot, heat the oil. Add the onion and cook over moderate heat until softened, about 7 minutes. Add the cabbage, ginger and turmeric and season with salt. Cook over moderate heat, stirring occasionally, until the cabbage is wilted, about 5 minutes. Add the cream, cover and simmer over moderately low heat, stirring occasionally, until the cream has thickened, about 8 minutes. Stir in the kale, season with salt and cook for 3 minutes, stirring a few times. Remove from the heat and stir in the buttermilk. Bring to a simmer and serve.