Strip the leaves from the stems of the kale and choose the crisp and curly ones for use, wash through two waters and drain. Boil in salted water twenty minutes, then pour into a colander and let cold water run over it, drain and chop fine. Brown the onion in the butter, and add the kale, seasoning with salt and pepper, add a half teacupful of the water in which the kale was boiled, and let all simmer together for twenty minutes. Just before taking from the stove add the milk or cream, thickening with a little flour. Let boil a moment and serve.