There are several key ingredients that distinguish an excellent paella. Saffron threads are arguably the most important; these tiny strands possess a deep, earthy, musky flavour and merely a pinch will promote intense colour and flavour. Sweet paprika adds a little smokiness; tomatoes contribute sweetness and depth.
Calasparra or bomba rice will give the perfect paella texture — this firm, round, medium-grain rice cooks to a slightly sticky yet dry finish without being glutinous. Look for rice labelled ‘Valencia rice’ or ‘rice for paella’. Arborio or another risotto rice can be substituted but the result will be a little stickier.
Stir the rice as little as possible to discourage the starches from being released or the rice will end up mushy.
Paella derives its name from the special pan (doubling as a serving vessel) in which it is cooked. The paella pan, or paellera, is a wide, shallow pan most often made from cast iron, but also seen in earthenware. The pans have no lid, but usually have a round handle on one or both sides. Paella pans are now widely available at cookware stores or special Spanish food stores.