Fish ‘Pahlavan’ with a Walnut and Tarragon Tarator

Pahlavan-anything in Iran indicates big, fit for a king (reputedly like the Pahlavi shahs of the country), but it is a particularly common expression in relation to cooked fish. It is my firm belief that it is used in the context of fish on a restaurant menu when either they know not which fish they are serving, or when the chef reserves the right to serve whatsoever fish he jolly well pleases. Most often in the Iranian restaurants of London, Mahi Pahlavan is, at least current