Before paella became the elaborately coded, fiercely regional, internationally misunderstood dish it is today — before the debates over whether chicken belongs in it, whether chorizo is an abomination, whether the socarrat crust is optional or mandatory — it was simply arròs, rice, cooked in a wide flat pan over orange wood, with whatever protein the Valencia wetlands provided that morning.
The earliest documented paella recipes from the rice-farming communities around the Albufera lagoon in Valencia — recorded by the agricultural writer Francisco Martínez Montiño in the eighteenth century and by the rice merchants of the Mercado Central a century later — include shrimp and peas far more frequently than they include rabbit or chicken, which were Sunday additions, special-occasion proteins. The everyday version was built from the lagoon's abundant shellfish and the frozen pea that Valencian market gardens had been producing since the Arab agricultural revolution of the ninth century.
The technique of pressing the rice flat into the pan and leaving it entirely undisturbed — no stirring, no fluffing, trusting the heat — is the single most important principle of the Valencian tradition. It produces a crispy bottom layer, the socarrat, that is simultaneously the most prized and most feared element of rice cooking: prized for its toasted, caramelized depth, feared for its proximity to burning. The skillet version brings this ancient technique into twenty minutes.