M&S British Soured Cream 'I’ve always been keen on a baked potato with sour cream and chives and, indeed, sour cream has many savoury applications (it’s a wonderful base for a fresh horseradish sauce, mixed into mayo for a tangy dressing, stirred into soups or a pan of garlicky mushrooms) but I’m becoming more and more convinced that a splodge of it is quite the best accompaniment for a rich chocolate cake or pudding. I must also inform you that it is perfect with that old-fashioned delight, a baked apple or, indeed, a crumble.' Nigella Lawson