You don't think fried fish can migrate? You underestimate it -- or you underestimate at least one fried fish tribe, which has made it from Spain to England, China and many points in between, including your local Mexican restaurant.
This particular tribe has been coated in a sort of edible body armor made of eggs thickened with flour or bread crumbs to a suitable consistency, which is one of the best available answers to the age-old question: How do you keep a fish from falling apart under heat, from sticking to the pan and breaking up when it's turned over?
You'd think this clever idea would have occurred to lots of people, but it looks as if it was invented just once, in the Iberian Peninsula sometime in or before the 1200s, because the first description appears in a 13th century Moorish cookbook written in Arabic. The recipe for hut mu'affar starts with fillets of fish. (The fish has been lightly poached first to make the fillets easier to separate and bone.) It continues: "Then take ground bread crumbs or wheat flour and add eggs, pepper, coriander, cinnamon and spikenard, beating them all together. Roll the pieces of fish in it over and over, then fry in fresh oil until browned."
This was served with an oil and vinegar dressing flavored with cumin and soy sauce, which sounds pretty good. The spices in the flour don't sound bad to our tastes either ... except perhaps for the spikenard, a resinous aromatic mostly used in hair tonics.
The name hut mu'affar means "dusted fish." So the original technique might have been to dip the fish in eggs and then "dust" it with the bread crumbs, rather than beating the eggs and crumbs together to make a batter. There's not a huge difference, anyway, between mixing the crumbs and eggs in a bowl or on the surface of the fish. The two techniques are often found side by side.
By the way, the Moors also fried eggplants in batter using the mu'affar technique. The reason is obvious -- eggplant slices also tend to fall apart in frying, not to mention that they absorb ridiculous amounts of oil if you don't coat them. Now the door was open for the invention of other fried vegetable dishes.
By the 16th century, the Portuguese were in the habit of eating batter-fried fish and vegetables during the four major fasts of the year, known as the quattuor tempora in Latin. Portuguese merchants brought the idea with them when they traded with Japan, and the Japanese enthusiastically adopted the idea, along with the name "tempura." One of the things they tempuraed, of course, was fish.
Meanwhile, Sephardic Jews fleeing Spain took the batter-fried fish concept to England in the 17th century. English gourmets learned about "fish fried Jewish fashion," and recipes for it eventually started appearing in cookbooks. The 19th century Anglo-French chef Alexis Soyer observed that Jewish fish was often served with oil and vinegar dressing -- just like the medieval hut mu'affar. His recipe became widely known on both sides of the Atlantic; Thomas Jefferson's granddaughter copied it into her own personal collection.
There had been Jewish fried fish shops in London for quite a while when Irish immigrants fled there in the 1840s to escape the potato famine. The Irish opened their own fried potato shops, and toward the end of the 19th century the two combined to make the famous English institution of the fish and chips shop, where to this day the preferred flavoring is still a medieval one, vinegar.
Meanwhile, Japanese emigrants were taking tempura wherever they went. Chinese cuisine now employs a lot of batter coatings for fried food, typically using cornstarch and only the whites of eggs. But is this an ancient Chinese tradition or a borrowing from the Japanese?
"Battered fried shrimp and such are mostly modern," says Eugene Anderson, a professor of anthropology at UC Riverside who specializes in Chinese food ways, "and probably derived either from tempura or from Western cooking." He qualifies this by pointing out that China is a vast place and no detailed history of Chinese regional cuisines has yet been written.
Still, he doubts that batter frying has a long history in China, partly because the Chinese have traditionally been so thrifty in their use of oil. "The normal way to fry shrimp in old China was just to stir-fry them," Anderson says. "Deep-frying was not common, and very rare for seafood."
The story goes on. Since 1983, the Rubio's Fresh Mexican Grill chain has popularized the fish taco in 150-odd locations in the western states. And what is a fish taco? It's ... well, tempura in a tortilla. The fish taco, it seems, developed in Baja California after Japanese fishermen were brought to Ensenada in the 1920s to teach fishing and diving techniques.
The medieval fried fish recipe has now been to England, Japan, China, Mexico and in fact all around the world, with each regional stop adding its own variations. Along the line, it has swept vegetables into its path -- creating not only tempura but probably American fried zucchini and Mexican chiles rellenos too (hey, hello to Mexico again!).
It's been a long, strange trip from the Moorish hut mu'affar in a batter flavored with spices (and something that smelled like Vitalis) to the frozen beer-batter fish stick. To say nothing of Southern deep-fried pickles and (gulp) the deep-fried candy bar.
Or rather, a long, very strange fried fish migration.