January, the month of citrus and that all important Rhubarb Triangle. Like us forced rhubarb has survived months of darkness, only to emerge, bright, rosy, and ready to be thrust into any situation, be it sweet or savoury. This loaf is utterly scrumptious, a sour tang from rhubarb and sourdough discard, an earthiness from Assam tea and the sweetness that we all migrate to with a good cake, all boxes ticked…