The mother of all one-dish meals, paella is a supreme party dish. Improvisation, within reason, rules: Even in Spain the ingredients in paella are hotly disputed, making it impossible for foreigners, let alone Spaniards, to dictate them strictly. Its origins are ancient, rooted in the area around Valencia near the Albufera Lagoon, where both fishing and rice growing dominated. It is the food of farm workers who cooked a dish of rice and ingredients at hand over a wood fire in a wide, shallow pan, from which the dish gets its name. It is still often cooked outdoors over an open fire.
While the ingredients may vary, ranging from snails, chicken, and lobster to chorizo and ham, the method follows a few rules. Start with steeping crumbled saffron in hot stock or water. Then build a sofrito, or base, of slowly cooked, finely chopped vegetables such as onions, garlic, and red peppers. Add the rice to the pan and stir to coat it with the sofrito and lightly toast it. Stir in the stock and spread the rice in the pan. Leave it to simmer and absorb the liquid without stirring, moving the pan every so often to distribute the heat. Since the dish was invented outdoors, cooking on the stovetop has its limitations; to imitate the direct heat of the fire, straddle the pan over two burners if possible. Finally, add the seafood and transfer the pan to the oven to finish cooking. (If you are anxiously awaiting latecomers, you can stall the cooking: Lightly cover the pan with foil. When you want to proceed, reheat the rice on top of the stove and then add the seafood.)
The ideal rice for making paella is a medium-grained, stubby rice that absorbs liquid well but maintains a degree of firmness in cooking. Spanish bomba rice is preferred, but it can be pricey and hard to find. A good substitute is short-grain rice. To achieve the crusty golden bottom layer of rice coveted by true paella lovers, called socarrat, you will need a wide, flat pan, so that the layer of rice in the pan is about ½-inch thick. You could buy an inexpensive paella pan, but a large skillet works just fine. Serve the paella in the pan like the Spaniards do, placed in the center of the table for all to help themselves. After you try this seafood version, you may want to create your own.