How to Make It
In a food processor, pulse the chorizo until very finely chopped. Transfer to a deep 12-inch skillet, add the 3 cups of canola oil and cook over moderately low heat, stirring occasionally, until the oil is well flavored with the chorizo, about 1 1/2 hours. Strain the chorizo oil through a fine sieve into a heatproof bowl; reserve the drained chorizo for another use (see Note). Return the strained oil to the skillet.
Meanwhile, light a grill or preheat a grill pan. Brush the corn with canola oil and season with salt and pepper. Grill over moderate heat, turning, until lightly charred and crisp-tender, 5 to 7 minutes. Transfer the corn to a plate and let cool completely, then cut the kernels off the cobs.
In a large bowl, whisk the mayonnaise with the lime zest and juice, smoked paprika and olive oil and season with salt and pepper. Fold in the corn kernels, cilantro and scallions.
Heat the chorizo oil until it reaches 160° on a candy thermometer; adjust the heat as necessary to maintain the temperature. Pat the fish fillets dry and season them with salt and pepper. Carefully slide the fillets into the chorizo oil and poach until just white throughout, about 12 minutes. If the fillets are not completely submerged in the oil, turn them halfway through poaching. Using a slotted spatula, transfer the fish to paper towels and blot dry. Serve with the grilled corn salad and lime wedges.
The drained chorizo can be spread on a foil-lined rimmed baking sheet and baked at 200 degrees for about 2 hours, until crisp. The crispy chorizo bits can be sprinkled on salads, eggs or baked potatoes.