For the fish sticks:
Cut the fish into sticks about 3 inches long and 1/2-inch thick. Combine the breadcrumbs, coconut, cornmeal, curry powder and 1/2 teaspoon salt in the bowl of a food processor and pulse until the coconut is coarsely chopped. Dump out into a shallow dish. Whisk the egg white with 1 tablespoon water in another shallow dish.
Dip the fish into the egg white, shake off the excess and coat thoroughly in the breadcrumb mixture. Bake immediately, or refrigerate up to 1 hour before baking. To freeze, arrange the breaded fish sticks on a baking sheet and freeze until hard, 1 to 2 hours. Store in re-sealable freezer bags for up to 1 month.
For the sauce:
Combine the yogurt, carrot, 1 tablespoon water, sweet chile sauce, soy sauce, scallions, lime juice and salt to taste. Wrap and refrigerate until ready to serve.
Preheat the oven to 425 degrees F. Fit a rimmed baking sheet with a baking rack and spray with cooking spray. Generously spray the fresh or frozen fish sticks all over with cooking spray. Arrange on the baking rack and bake, flipping halfway through, until golden and crispy and cooked through, 15 to 20 minutes (if frozen, 20 to 25 minutes). Remove from the oven and season with salt. Serve with the dipping sauce.