Dehesa's expertise is supposedly in the nose-to-tail department – think ox heart and sweetbreads – but what captivated me was the unassuming tortilla. Here, the Spanish classic features soft chunks of potato and jamon embedded in a slightly wet omelette and fried to a smoky, brown crisp on the surfaces. A generous slathering of piquant Romesco sauce (at least I think that's what it is) as the finishing touch made this utterly impossible to resist.