Butterflied Trout with Spicy Lettuce, Celery, and Herbs

Using the side of a chef's knife, mash jalapeño, lime zest, and orange zest with a pinch of salt on a cutting board to a paste. Transfer to a medium bowl and mix in shallot, orange juice, lime juice, fish sauce, and soy sauce. Season dressing with salt and pepper. Season trout with salt and pepper. Heat 1 tablespoon oil in a large skillet over medium-high. Cook 1 trout, skin side down, until golden brown and crisp, about 4 minutes (flesh will be nearly cooked through). Remove from heat, turn fish, and let sit until cooked through, about 1 minute more. Transfer trout to a platter. Wipe out skillet; repeat with remaining trout and 1 tablespoon oil. Toss lettuce, celery, celery leaves (if using), cilantro, mint, and 3 tablespoons dressing in a large bowl; season with salt and pepper. Top trout with salad and spoon remaining dressing over.