Preheat. Preheat your grill to 400 degrees F.
Make the seasoning. Combine all ingredients for the blackening seasoning in a small bowl. Liberally season all sides of the cod fillets.
4 cod fillets, 1 Tablespoon smoked paprika, 2 teaspoons salt, 1 teaspoon onion powder, 1 teaspoon garlic powder, 1 teaspoon cayenne pepper, ¾ teaspoon fresh ground white pepper, ¾ teaspoon cracked black pepper, ½ teaspoon dried thyme leaves, ½ teaspoon dried oregano
Sear the cod. Place a 12-inch large skillet (preferable cast iron) on the grill grates to preheat. Drizzle in the avocado oil. When the oil just starts to ripple and smoke, place the cod fillets in the skillet. Sear for 3-4 minutes or until a beautiful crust has developed on the seasoning.
3 Tablespoons avocado oil
Finish cooking. Flip the fillets over, turn the heat down on the grill to 350 degrees F and close the lid of the grill. Cook for an additional 10-12 minutes, or until the internal temperature of the fish reaches 145 degrees F and flakes easily with a fork. If your fillets are really thin, they will cook faster, if they are thick, they will take a little longer. Use a thermometer to track your internal temperature so you don’t end up with over- or undercooked fish.
Serve. Remove the cod from the grill to a serving dish. Serve immediately.