method
1. Trim the spinach, removing any coarse stalks and brown or damaged leaves. Wash well in several changes of cold water, making sure all the grit is removed. Drain in a colander.
2. Place the minimum of water 1 cm (1/2 inch) is ample - in the bases of one or two large saucepans. Add the spinach and season generously.
3. Cover tightly and cook over a moderate heat for about 10 minutes, until tender. Push down and turn the spinach over once or twice during cooking.
4. Drain in a colander and press firmly with a potato masher to extract all moisture; chop roughly.
5. Melt the butter in a medium saucepan, add the spinach with plenty of seasoning and cook over a moderate heat, stirring occasionally, until piping hot.
6. Add a generous grating of nutmeg and spoon into a serving dish.