How to Make It
In a food processor, puree the onion, scallions, garlic, bell pepper and serrano with the thyme and parsley. Add the boiling water and pulse to incorporate. Let cool to room temperature. Add the lime juice and peanut oil and season with salt. Pulse briefly, then transfer to a serving bowl.
Rinse the cod and pat dry. Using your hands, shred it into small pieces, then chop it very finely. In a large bowl, whisk the flour with the baking powder. Add the eggs and ice water and whisk just until combined. Fold in the chopped cod along with the onion, garlic, bell pepper, chile, thyme and black pepper.
In a large, deep skillet, heat 1 inch of vegetable oil to 375°. Working in batches, scoop tablespoon-size mounds of batter into the hot oil and fry, turning once, until the fritters are deeply golden all over, about 1 1/2 minutes. Drain on paper towels. Transfer to a platter and serve hot, with the pepper sauce.
The pepper sauce can be prepared and refrigerated for up to 3 days.