In the pantheon of great international party dishes, you’d be hard-pressed to find one more misunderstood than paella.

Here’s what paella is not: It is not a yellow rice casserole. It is not a repository for all manner of meats and vegetables. It is not the Spanish national dish.

What paella is is a method of cooking rice, native to Valencia on Spain’s eastern coast, that involves sauteing ingredients in olive oil in a wide, shallow pan, adding rice and liquid and then cooking, uncovered and with a minimum of stirring, until the rice is just tender.

Penelope Casas, an authority on Spanish food (and the author of many cookbooks), explained that the name refers to the pan in which paella is cooked. “The paella – the pan – is wide and shallow,” she said. “It is made from carbon steel, it heats up quickly, and over time it discolors and gets ugly-looking.” (In other words, don’t spend your money on a $200 paella pan; you can get the real thing for about $40.)

In Valencia, Casas said, there are restaurants devoted to making paella. Some make the dish in their kitchens, others use a specially made propane burner-on-a-tripod, still others cook paella in the most traditional way: over an open wood fire.

Paella is a method of cooking rice, native to Valencia on Spain's eastern coast, that involves sauteing ingredients in olive oil in a wide, shallow pan, adding rice and liquid and then cooking, uncovered and with a minimum of stirring, until the rice is just tender.

In her definitive book “Paella! Spectacular Rice Dishes From Spain” (Henry Holt), Casas adapts traditional recipes for the American home cook. And she is bullish that a true paella requires nothing that can’t be easily obtained in most supermarkets. “The only indispensable ingredients are rice, water and olive oil,” she writes. “Everything else is the subject of endless debates and discussions by Spaniards.”

When Casas published “Paella” in 1999, short-grain Spanish rice was hard to find on U.S. shores. But the recent push by Spain to introduce its foods to Americans has brought many more imported products into specialty stores. Optimally, Casas would have us use the highest-quality Spanish short-grain rice, called Bomba, for paella. But she has also made entirely creditable – if unusually creamy – paellas with Italian Arborio rice; she particularly likes Beretta’s Superfino brand.

The yellow color of some paellas comes from saffron, but Casas said that it is really a supporting player most of the time. Still, it’s worth seeking out high-quality, authentic Spanish “thread” saffron that hasn’t been pulverized into an orange powder. Ditto Spanish paprika – pimenton – which has a haunting, smoky quality all its own.

Casas labors mightily to combat the notion, widely held by Americans, that “paella is a random assortment of seafood, meat and vegetables.” Even in Valencia, she said, restaurants now serve such ” mixed” paellas “because the tourists want them,” but the Valencians don’t really approve of them. “By mixing, you detract from the integrity of the main ingredients,” she said.

On the other hand, Valencia boasts an almost infinite variety of paellas, more than 60 of which Casas presents in her book. “Of course, there’s a tremendous variety,” she says. “Where paella comes from, they eat it every day.”