The basic recipe for arroz con leche, or Spanish rice pudding, is thought to have arrived in Spain during the Moorish period. Arroz con leche is a rice-based sweet treat produced by slowly simmering the rice in milk while gradually adding the remaining components.
Invasion of the Iberian Peninsula, which includes modern-day Spain, by the Moors began in 711 and lasted until the end of the 15th century, when they were fully pushed out. Rice pudding dishes, such as cinnamon and rice mixes, are part of classic Arabic cuisine, leading to the assumption that arroz con leche originated with Moorish influences.
The original recipe for arroz con leche was carried to South America during the Age of Exploration, when it spawned a slew of regional variations. Cinnamon, raisins, and vanilla are common flavour enhancers in Spanish rice pudding recipes. Other ingredients may be used in South American variants of arroz con leche, such as nutmeg and butter in the Costa Rican version and chocolate and cayenne pepper in the Mexican version.
Apart from the rice, milk, and sugar, the key components in the traditional Spanish arroz con leche dish include egg yolks, cinnamon, and lemon rinds. The rice is boiled in milk and must be regularly stirred to avoid burning the rice at the bottom of the pot. The remaining ingredients are cooked in milk before being added to the boiling rice. The meal can be served hot or cold once it has been cooked.