Preheat your oven to 425°F and line a baking sheet with parchment paper.
Slice the Russet potato into uniform wedges and toss them with half of the avocado oil and half of the sea salt.
Spread the potatoes on the baking sheet and roast for 25-30 minutes until golden and crisp.
While potatoes roast, pat the cod fillets dry with a paper towel and season with garlic powder, paprika, and the remaining salt and pepper.
In a medium bowl, whisk together the flour and cold light beer until a smooth, thick batter forms.
Heat the remaining avocado oil in a large non-stick skillet over medium-high heat.
Dip each cod fillet into the batter, allowing the excess to drip off, then carefully place in the hot skillet.
Sear the fish for 3-4 minutes per side until the batter is golden brown and the fish flakes easily with a fork.
Serve the crispy cod immediately with the hot potato wedges.