Cut the potatoes into strips. You can leave the skin on or peel the potatoes before cutting them. Place the potato strips in a large bowl of cold water. Let sit for 30 minutes to 1 hour.
Drain the potatoes and pat dry with paper towels. Place the potatoes into a large mixing bowl.
Add the cornstarch, oil, and salt and toss to evenly coat the potatoes.
Spread the potatoes out in the basket of your air fryer. Cook at 360 degrees F for 5 minutes. Shake the basket - making sure no fries are stuck together or to the bottom. Cook for another 10 minutes, shaking after 5 minutes.
Fish
While the fries cook, mix the flour, paprika, garlic powder, onion powder, salt, and pepper together in a shallow bowl. To another shallow bowl, add the bread crumbs. In a third shallow bowl, beat the egg. Now the dredging station is ready.
Pat the fish pieces dry with paper towels. Season both sides of each piece with salt and pepper.
Dip the fish piece first into the flour, then the egg, and finally the bread crumbs to coat all sides.
Once the fries have cooked for 15 minutes, carefully place a rack over them in the air fryer basket. (This will keep the fish and chip from touching.) Place the fish pieces on the rack in a single layer and spray with avocado oil.
Cook at 360 degrees F for 10-12 minutes. Check halfway through and stir the fries if needed. (You will need to remove the rack to do this. Be careful, it's hot!)
Plate the fish and then chips and serve warm with lemon wedges, tartar sauce, and/or remoulade for dipping.
Notes
You can choose what potatoes to use depending on your preferences. Starchy potatoes like Russet potatoes will be more fluffy inside after baking. While waxy/low starch potatoes like fingerlings or red bliss potatoes will be more creamy inside. Both are delicious.
Depending on the size of your air fryer you might need to cook in batches.
If you have an instant-read thermometer, you can check the fish for doneness. It should be 143 degrees F for done and 133 degrees F for glassy. Cooking time depends on the thickness of the fries and the fish. Please check your food a couple of minutes before cooking time is finished.