For the Fries: Peel and slice the potatoes into your desired fry size, then soak them in ice-cold water for 20 minutes.
Pat the potatoes dry with a paper towel. Season with cornstarch and and one portion of the seasoning mix.
Air Fry the potatoes at 380°F / 193°C for 20 minutes, shaking halfway through the cooking time.
For the Fish: Cut cod fillets into 6-inch pieces.
In a bowl, mix together the eggs, flour, milk, and one portion of the seasoning.
Dip each fillet into the batter, then coat it in panko bread crumbs mixed with the remaining portion of the seasoning.
Spray oil onto each coated fillet. Air Fry at 385°F / 196°C for 12-14 minutes, flipping halfway through.
For the Tartar Sauce: Mince the garlic, and dice the onions, pickles, chives, and dill.
In a bowl, combine the minced garlic, diced onions, pickles, chives, dill, mayo, sour cream, lemon zest, lemon juice, sugar, garlic salt, and pepper. Mix until well combined.