Using paper towels, thoroughly dry the fish fillets. This ensures that the dredge batter will stick. Do not skip this step - it's important.
Heat oil in a very shallow dutch oven or deep fryer to 375°F/190°C.
In a wide shallow bowl, place ⅓ cup of corn starch for dredging.
Whisk together all the dry ingredients for the batter (flour, corn starch, baking soda, paprika, garlic powder, salt and white pepper).
Once the dry ingredients are thoroughly combined, slowly add in the beer until the desired batter thickness has been achieved. It should be runny but not thin - close to pancake batter YOU MAY NOT NEED THE WHOLE CAN! Clumps are okay, and actually better. Do not overmix.
Once the pan or deep fryer has reached 375°F, take your dried fish and sprinkle with salt and white pepper. Dredge in the corn starch, then dip in the batter making sure to shake off the excess.
Immediately place the fish into the deep fryer or pot, being sure to not overcrowd it. Cook for 2-3 minutes per side, until the fish is golden brown and cooked through to 145°F.
Once fully cooked and browned, place the fish on a cooling rack lined with paper towel to absorb the excess liquid. Serve immediately with tartar sauce, a lemon wedge and fries if desired.