Paella Pizza? Purists Object to Variations of the Popular Spanish Dish

“I couldn’t even understand what mussels and clams on top of a pizza had to do with paella,” Ms. Bou said. She keeps the picture of the pizza “as proof of the atrocities committed against the Spanish traditional dish,” she said.

Paella’s international popularity is booming. Chefs and home cooks around the world have developed their own variations on the rice dish, and it has its own emoji.

In Valencia, the Spanish port city where paella is from, officials are hoping to have the dish recognized as “intangible cultural heritage” by Unesco, the United Nations Educational, Scientific and Cultural Organization. Paella would be on a list that includes such things as sauna culture in Finland and Neapolitan pizza making.

Purists fear all the attention is perverting traditional paella. Others say Spain should be proud of the dish’s expanding appeal.

Pablo Pérez, who works for an American bank in New York, got excited when paella was the featured dish in his office cafeteria. But the yellow rice with pieces of chorizo that he was served wasn’t paella, Mr. Pérez said.

“I felt offended, it was like an attack on our culture,” he said.

Traditional paella’s list of acceptable ingredients is limited: rice, vegetables, chicken, rabbit or seafood. Chorizo or onions don’t belong, purists say, arguing unofficial additions turn paella into a plate of rice with stuff.

In traditional recipes, meat and fish can’t be mixed. Valencian paella has chicken, rabbit and some vegetables, such as green beans or butter beans. There are different versions of seafood paella, usually without vegetables.

When British chef Jamie Oliver posted his recipe for paella in 2016, Twitter erupted with thousands of replies from indignant traditional paella defenders who objected to the inclusion of chorizo.

“My version of fish and chips combines aubergines with duck,” Spanish journalist Antonio Villareal replied on Twitter.

“In Spain we all have different ways of preparing paella and sometimes we mock the purists from Valencia, when they defend the authenticity of their paella version,” Mr. Villareal said. “However, when an English person or an American creates their own version, all Spaniards respond offended.”

Mr. Oliver didn’t respond to a request for comment. The recipe remains on his website, which notes: “The Spanish can be quite protective about what is and what isn’t a paella, but at the same time, the spirit of their cooking has always been flexible to whatever meat, fish, seafood or game can be found.”

Wikipaella, a website founded by three Valencians, promotes “authentic paella” and promises to “publicly report any transgressions committed against paella, particularly those taking place in the Valencian Community.”

Paco Alonso, one of the Wikipaella founders, says he once saw a paella served in one of Valencia’s main squares, Plaza del Ayuntamiento, with fried eggs on top of it. He said the restaurant closed months later.

Wikipaella says restaurants can apply to have their versions “certified” if the group determines the dish has been cooked following the traditional recipe. Certified paellas can be found in Munich, Bogotá or Las Vegas, according to the website.

“I have been investigating paella for 30 years because I feel that it is the most difficult rice dish to cook in the world,” Mr. Alonso said.

Paco Parreño, a Valencian and head chef of the Spanish restaurant La Nacional in New York, says the reason Valencians are puritanical about paella is the high value they give to local ingredients.

“We shouldn’t be fighting against other versions of paella, it is to be appreciated that people from other countries are interested in our gastronomy, even when they eat it in their own style,” the chef said.

Purists had to loosen up the strict requirements on Sept. 20, World Paella Day.

“It’s a day to celebrate, beyond recipes and ingredients, the internationality of the paella,” said Miguel Ángel Pérez, brand and markets director at Visit Valencia, one of the organizers.

There were events in 30 countries, including one in Valencia: the World Paella Cup. In that competition, 10 chefs competed, including a chef from South Korea who prepared his paella with kimchi and ginseng. An Irish chef used oysters and Guinness beer.

“For me, it was very tasty and interesting,” Mr. Pérez said about the Guinness paella. The winner, with a more traditional recipe, was Spanish chef Noelia Pascual. U.S. chef Natalie Curie, who included pork ribs, came in second place.

In Valencia, many chefs are featuring the dish as part of a restaurant week beginning Thursday. Chef Nacho Romero is planning a paella of Iberian pig, pumpkin, young garlic and cauliflower. As most of the customers are locals, he wanted to do something different, he said.

“It’s a paella using seasonal winter products,” Mr. Romero said. “Paella was the dish of the working class and they cooked it with the local ingredients of the season, that’s why there are so many different paellas,” he said.

Camila Zuluaga, a Colombian tourist visiting Spain, ate her first “paella del senyoret” or “the lord’s paella.” In this version, the seafood is peeled, so the lord’s fingers don’t get dirty.

Before leaving Spain, she went to the supermarket to buy ingredients for paella. When she had to choose between Spanish paprika or spicy paprika, she picked the latter.

“Maybe we can create an improved version of the paella,” she told her Spanish boyfriend. He called it a sacrilege, Ms. Zuluaga said. “He said that wouldn’t be a paella.”