Preheat your air fryer to 400°F and lightly coat the basket with a small amount of oil.
Slice the russet potato into thin, even wedges and toss them in a bowl with half of the avocado oil and a pinch of sea salt.
Place the potato wedges in the air fryer basket in a single layer and cook for 15-18 minutes, shaking halfway through, until they are golden and crisp.
While the potatoes cook, pat the cod fillets completely dry with paper towels and season both sides with sea salt, black pepper, and garlic powder.
In a small shallow bowl, whisk together the all-purpose flour and light beer until a smooth, thick batter forms that coats the back of a spoon.
Dip each seasoned fish fillet into the beer batter, allowing any excess to drip off, and lightly brush or spray the exterior with the remaining avocado oil.
Once the potatoes are done, remove them and keep warm; place the fish in the air fryer basket and cook at 375°F for 10-12 minutes until the coating is crunchy and the fish flakes easily.
Steam the green peas in a small amount of water until bright green and tender, then serve immediately alongside the crispy fish and potato wedges.