Soak potatoes in ice water for at least 30 minutes.
Preheat air fryer to 400 degrees.
Dry potatoes and toss with 1/2 tsp salt, pepper, and oil.
Air fry for 10 minutes, rest for 5 minutes.
Add additional oil and cook for another 10 minutes.
Remove from air fryer and sprinkle on remaining salt.
Combine 1 cup flour and corn starch, set aside.
Mix remaining flour with seasonings and beer.
Dip fish into wet batter, then coat with flour/corn starch mixture.
Place fish inside air fryer in a single layer.
Spray generously with canola oil and fry at 400 degrees for 10 minutes.
Turn fish, spray with oil, and cook for another 5 minutes.
Serve with malt vinegar, tartar sauce, or dipping sauce of choice.