Bring three quarts of oil in a heavy pot to 350 degrees Fahrenheit. Slice the fish into finger-width strips and set aside.

Make the tempura batter by mixing together the flour, cornstarch, baking powder, and salt. Whisk in the egg yolk, cold seltzer, and the mustard. Place the cut fish in the tempura batter and set aside while you make the pico de gallo and chipotle crema.

To make the pico de gallo, mix together the diced tomato, onion, cucumber, and jalapeno. Add the minced garlic, lime juice, chopped cilantro, and season with salt to taste. Set aside till later.

Make the chipotle crema by combining the sour cream, mayonnaise, lemon juice, the chopped chipotle, and the adobo sauce. Set aside.

Fry the battered fish in the hot oil until cooked through and crispy. Once done remove the fish and season with salt.

Warm the tortillas in a hot pan and prepare the garnishes of wedged limes, radishes cut in thin rounds, and shredded cabbage.

To build, place two overlapping tortillas on a plate. Add a smear of the chipotle crema, the fried fish, and some pico de gallo. Top with the shredded cabbage, a squeeze of lime juice, and some radish rounds.