Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
Trim the woody ends off the asparagus and place the spears on the prepared baking sheet.
Drizzle the asparagus with the olive oil and season with 0.25 tsp of the sea salt and 0.125 tsp of the black pepper.
Roast the asparagus for 12 to 15 minutes until tender-crisp and slightly browned.
In a small bowl, combine the smoked paprika, garlic powder, onion powder, oregano, thyme, cayenne, and the remaining salt and pepper.
Pat the cod fillets completely dry with paper towels and coat both sides generously with the prepared spice mixture.
Heat the avocado oil in a cast-iron or heavy-bottomed skillet over medium-high heat until shimmering.
Carefully place the cod in the hot skillet and sear for 3 to 4 minutes per side until a dark crust forms and the fish flakes easily with a fork.
Plate the blackened cod alongside the roasted asparagus and serve immediately with a fresh lemon wedge.