The main ingredient in a traditional Spanish paella is rice, specifically a short-grain variety known as Bomba or Calasparra. This rice absorbs flavors well and maintains a firm texture during cooking. Paella originated in the Valencia region of Spain and is known for its vibrant colors and varied ingredients, which can include vegetables, saffron, seafood, and meats like chicken or rabbit. The dish is typically cooked in a wide, shallow pan called a paellera over an open flame, allowing the rice to develop a crust known as socarrat at the bottom.