Technically a stem, honestly a fruit, secretly a saviour.
Forced rhubarb from Yorkshire's Rhubarb Triangle arrives in January when nothing else is happening. Field rhubarb turns up from March. Bright, tart, indestructible in a compote, and just as happy alongside mackerel as it is in a crumble. Learn to embrace the sharpness — sugar is only half the answer.
Any greengrocer, or grow it yourself — it's practically impossible to kill.