Preheat oven to 220 degrees C. Line a baking tray with aluminium foil and lightly spray with cooking spray. Mix milk and ranch dressing in a shallow bowl. Place flour in separate bowl and set aside.
Mix together bread crumbs, Parmesan cheese, all purpose seasoning, black pepper, celery salt, garlic powder, onion powder, paprika, parsley and basil in a bowl.
Spray bread crumb mixture with cooking spray until damp, then stir bread crumbs. Repeat spraying and stirring 3 more times to lightly moisten crumb mixture with cooking spray.
Transfer crumb mixture to a large resealable plastic bag. Gently press the hoki fillets into the flour to coat then sake off the excess flour. Dip the fillets into the ranch dressing mixture. Place all the fillets into the resealable plastic bag; seal bag and shake to coat fish with bread crumb mixture.
Arrange hoki on prepared baking sheet. Lightly spray the breaded fish with cooking spray. Bake in the preheated oven until the fish is easily flaked with a fork, 20 to 25 minutes.
If you don't have hoki you can use any other local white fish such as gunard or tarakihi.