How to Make It
Preheat the broiler. Broil the red pepper and jalapeños until charred all over. Transfer to a bowl, cover with plastic wrap and let cool. Remove the skin, cores and seeds and finely dice the red pepper and jalapeños. Transfer to a bowl and stir in the mayonnaise, shallot, cilantro and lime juice. Season with salt and cayenne and refrigerate for at least 1 hour or overnight.
In a large bowl, cover the catfish with the buttermilk and refrigerate for 1 hour. Heat a large cast-iron skillet. One at a time, cook the tortillas over moderate heat until swarmed through, about 15 seconds per side. Stack the tortillas, wrap in foil and keep warm. On a large plate, combine the masa harina, cornmeal, cornstarch and salt. Remove the catfish strips from the buttermilk, shaking off any excess, and coat them with the cornmeal mixture.
Heat 1/2 inch of canola oil in the large skillet. Working in batches fry the catfish over moderate heat, turning occasionally, until golden brown and cooked through, about 4 minutes. Transfer the catfish to a wire rack set over a baking sheet to drain.
In a medium bowl, toss the lettuce with the lime juice and 1/4 teaspoon of kosher salt. Spread a generous tablespoon of the jalapeño remoulade on half of each tortilla and top with the catfish and lettuce. Fold the tortillas. Spoon the creamed corn onto 8 large plates and set a taco on top. Garnish with the pico de gallo, cheese, cilantro leaves and sour cream and serve at once.