Rice originated in Asia and, along with pasta, was brought to the Mediterranean by the Moors. When the Moors invaded Spain, they brought both products with them. The Moorish casseroles of rice and fish established the custom of eating rice in Spain.
Paella (pronounced pie-AY-ya) was originally made by agricultural laborers, who cooked the mixture of rice, snails and vegetables in a pan over an open fire in the fields. The original paella is made with two different kinds of beans (one a big white Valencian bean called “garrofón” and the other a green-flat bean), a meat mix (snails at first, then later chicken, rabbit and also duck). It was at first a communal dish, eaten directly from the pan with wooden spoons. Other Valencians closer to the coastline added eel and butter beans. The more elegant paellas loaded with chorizo, chicken and seafood did not evolve until living standards rose in the late 18th century, when the dish went upscale.