Sharbat-e rivas (rhubarb sherbet)
For a few weeks in spring, after Nowruz, sellers come down from the Alborz foothills, the mountains of Khorasan and Kurdistan with bundles of rivas, the thick-stalked wild rhubarb. People peel and eat the stalks raw with salt, cook them into khoresh, and boil the rest into syrup to keep the taste of the season into summer. Sharbat-e rivas is pink, sharp and refreshing, like sour cherry and green apple together, softened by sugar and lifted by mint. The common mistake is boiling the rhubarb hard and pressing it through the sieve, which makes the syrup cloudy, brownish and stringy; simmer gently and let it drip on its own. Use only the stalks, never the leaves, which are poisonous. The syrup is ready when it is clear, rose-coloured and coats a spoon in a thin film; it keeps for two weeks in a clean bottle in the fridge, and should be thrown away if it fizzes, smells of alcohol or grows mould. Garden rhubarb is a good substitute for rivas; the reddest stalks give the prettiest colour. Chef's tip: a strip of lemon peel in the pot brightens the colour and stops the syrup tasting flat.
























