In a large bowl, whisk together flour, cornstarch, garlic powder, cayenne, paprika, baking powder, and salt and pepper, to taste. Reserve about ¾ cup of the flour mixture (this is used to dust fish). Set aside until ready to dip the fish.
Pour oil into a cast iron or skillet, enough for deep frying. Preheat oil to about 375 degrees F.
While the oil is preheating, add the beer to the bowl of the flour mixture and whisk until incorporated and the batter is smooth.
Then dip each fish strip in the dry flour mixture first, shake off any excess flour, and deep into the beer batter mixture until it’s completely covered. Remove the fish and let the excess batter drip off.
Carefully lower into cast iron, fry a few pieces at a time, moving them around so they don't stick. Fry until brown and crispy, about 3 to 4 minutes or more depending on the size.
Remove from the fryer with a slotted spoon place on a cookie or wire rack to ensure crispness. Repeat with the remaining fish strips.
Pour water into a large bowl, then add ice and vinegar. Set aside.
Then scrub the potatoes clean and cut them into a ¼ -½ inch thickness – thin fries are crispier and take less time to cook - make sure they are even for even cooking. A mandolin or French fry cutter works best if you have any.
Place them in the bowl of water and let it soak, 2 -3 hours. Soaking the fries gets rid of the starchy content which causes the potatoes to be soggy- not ideal
After the potatoes have soaked, drain them, and spread them on paper towels dry thoroughly.