Position racks in top and bottom thirds of oven. Preheat to 450F. Line 2 baking sheets with parchment.Toss potatoes with oil, paprika and 1/4 tsp salt on one prepared sheet until coated. Bake in top third of oven, flipping halfway through, until golden, 25 to 30 min. Pour flour into a shallow dish. Whisk egg in another shallow dish. Pour panko into a third dish.Pat fish dry with paper towels. Sprinkle with ¼ tsp salt. Cut crosswise into 1-in.-wide sticks. Dip each piece first in flour, then egg, then coat with panko. Lay on second prepared sheet. Lightly spray tops with oil. Bake in bottom third of oven until a knife tip inserted in centre of fish and held for 10 sec comes out warm, 8 to 10 min. Serve with chips and tartar sauce.

DIY tartar sauce
Stir together 1/4 cup each plain yogurt and mayo with 3 tbsp relish, 1 tbsp finely chopped dill
and 1/8 tsp salt.