A wilted spinach salad, simple and nourishing, offers an excellent way to incorporate fresh winter greens onto your supper table during the long, dark days of winter when hardy spinach is plentiful. Heating the spinach very slightly, as in this wilted spinach salad recipe requires, provides a dual purpose: not only does it make the dish more suitable for cold days when fresh, raw greens can be unappealing, but it also helps to mitigate the effects of oxalic acid - an antinutrient naturally found in spinach and other greens.