The story of the Baja-style fish taco supposedly begins with the Japanese fishermen who plied their trade off the west coast of Mexico as early as the 1920s. They naturally wanted to dine on the day’s catch and attempted to convey what they had in mind to the locals. What emerged from the kitchen was the fish tacoin essence, tempura wrapped in a tortilla. Pairing the clean precision of Japanese cuisine with the earthy savor of Mexican, the fish taco is what all fusion cuisine should be: coherent to the point of seeming natural and inevitable.

At Tonali, the most sophisticated of Durham’s numerous Mexican eateries, the signature fish tacos have a Japanese pedigree of their own. Chef-owner Andres Macias, formerly the executive chef at the University Club and sous chef at Four Square, used to spend his days off as a reverent fly-on-the-wall in the kitchen of Waraji, the Triangle’s best Japanese restaurant.

“For a whole year I drove to Raleigh and spent my free Mondays at Waraji,” says Macias. “I was fortunate that the owner allowed me to watch and learn.”

Watch and learn he did. When he opened Tonali in 2006, Macias used Waraji’s tempura as a template for his fish tacos. Like the best tempura, his deep-fried fish filets are crisp, greaseless and light.

Tonali’s tortillas, by contrast, emanate from deep within Macias’ family tradition and native culture. While many Mexican restaurants reheat packaged tortillas or make their own tortillas using packaged masa harina, Tonali produces its own masa, laboriously boiling and grinding hominy (dried corn kernels) in its modest kitchen. Macias’ wife, Juana, performs the delicate operation of forming the tortillas and laying them on the hot comal. Invariably, they gently balloon, indicating that the comal is sufficiently hot, the dough sufficiently moist and the tortillas sufficiently thin.

“In Mexico, moms teach their daughters to make masa,” says Macias. “Our cooking is from that whole world of traditional cuisine. I remember how my mom and my whole family used to cook. We use these same techniques but we take a little more sophisticated approach.”

This traditionalism produces a tortilla so tender and fragrant that fillings are almost a distraction. The home cook can approximate this tortilla by dispensing with the instant masa harina (“masa instantánea de maíz”) that dominates the suburban supermarket aisles and hunting down the nixtamalized masa harina (“harina de maíz nixtamalizada”) that is found only in well-stocked tiendas. Switching from instant to nixtamalized masa harina is like exchanging a green can of Kraft “Parmesan” for a wedge of Parmigiano-Reggiano. Suddenly you’re a good cook!

Chef Macias’ “sophisticated approach” to garnish entails arugula, pickled red onion (yet further Japanese influence?) and a vibrant mango salsa. The translucent lavender of the onion and electric yellow of the salsa lend the finished taco a look of postmodern cheer. One might call it a taco for the age of anime.

Tonali’s Baja-Style Fish Tacos with Pickled Red Onion and Mango Salsa

Pickled Red Onion
1 red onion, thinly sliced
1/2 cup water
1/4 cup sugar
1/4 cup white vinegar
Pinch of kosher salt

Mango Salsa
1 mango, ripe but not mushy
1/2 red onion
2 tbsp. finely minced cilantro
1 serrano chili pepper
1 lime, juiced
1 tbsp. canola, vegetable, or neutral olive oil
Kosher salt and pepper to taste

Corn Tortillas
275 grams (about 2 cups) nixtamalized masa harina (see notes)
420 grams (about 1 3/4 cups) water, at room temperature

Deep-Fried Fish Filets
135 grams (about 1 cup) all-purpose flour
45 grams (about 5 tbsp.) cornstarch
1/4 tsp. baking powder
1/4 tsp. chili powder
1/4 tsp. kosher salt
Pinch of black pepper
1 tsp. finely minced cilantro
260 grams (about 1 cup plus 3 tbs.) unflavored club soda or seltzer
1 lb. halibut, grouper, shark, tilapia or other fresh white fish
Canola oil, for deep-frying the fish

Pickled onion: Thinly slice the onion. Combine the remaining ingredients in a small saucepan and bring to a boil. Add the onion and simmer for 10 minutes, until the onion has become purple and translucent and the liquid has thickened into light syrup. Set aside to cool.

Mango salsa: Peel and dice the mango into -inch cubes. Dice the red onion. Finely mince the cilantro and serrano. Combine ingredients in a serving bowl and dress with lime juice, oil, salt and pepper.

Tortillas: In a large bowl, mix the masa harina and water. Knead to form a smooth, moist dough (see notes). Let the dough rest for five minutes. Detach a piece of dough and roll into a ball (about 35 grams, slightly smaller than a pingpong ball). Place between plastic sheaths (see notes) and flatten in a tortilla press. Peel the plastic from the top of the tortilla. Flip the tortilla onto the palm of the hand and peel the plastic from the bottom. Lay the tortilla on a hot pan (ideally cast iron) and cook until the tortilla has puffed and begun to char. Wrap the cooked tortillas in a clean kitchen towel to stay warm and moist. The tortillas will steam slightly in the towel, bringing them to final perfection.

Fish: Heat the canola oil in a cast-iron Dutch oven to 350 degrees. Whisk the dry ingredients until well blended. Add the club soda, whisking to form a loose batter (see notes). Slice the fish into 4-inch strips. Dip the fish in the batter and fry until crisp and golden, about two minutes.

Notes: Masa harina is a variety of corn flour. It is not to be confused with corn starch, a thickening agent that is unhelpfully called “corn flour” in the United Kingdom. Nixtamalized masa harina (“harina de maíz nixtamalizada”) is available at Tienda y Carnicería La Superior, 3325 N. Roxboro St., Durham, a full-scale Latino supermarket.

Transferring the fragile tortillas from the tortilla press to the griddle is tricky. Chef Macias offers one piece of valuable advice. While most cookbooks advise lining the tortilla press with plastic sheaths cut from supermarket checkout bags or sandwich bags, he recommends using the thinner plastic bags that supermarkets provide for produce. The tortillas indeed release more easily from the thinner bags for reasons we’ll leave to industrial chemists.

The tortilla dough should be maximally moist without being tacky or unmanageable. If the dough is granular or crumbly, it is too dry; if it sticks to the hands or bowl, it is too wet. Aim for a texture on the cusp of pastiness. Play-Doh is a useful reference point.

The fry batter will require slight adjustment depending on the brand and condition of the flour. It should have the consistency of a thin pancake batter. If a spoon leaves viscous furrows in the surfaceif the word “viscous” even comes to mindthe batter is too thick. Add small amounts of club soda as necessary. Thicker batter produces an indelicate result.

Minus the chili powder and cilantro, Chef Macias’ fry batter is the basis for an entire repertoire: onion rings, fried bananas, fried apple rings drizzled with honey, British-style fish and chips, Chinese-style salt-and-pepper fish or squid. For a classic Taiwanese disha Sino-Japanese hybrid batter and deep-fry a plateful of jumbo shrimp. Drizzle with sweet mayonnaise (equal parts mayonnaise and sweetened condensed milk) and garnish with pineapple. In Taiwan, this dish is often topped with rainbow-colored ice-cream sprinkles (very much optional).

Contact David Ross at david_liling@hotmail.com.

This article appeared in print with the headline “The secret of fish taco success.”