Mix 1 tablespoon chili powder, 1 teaspoon paprika, 1/2 teaspoon cumin, 1 teaspoon garlic powder, 1 teaspoon kosher salt, 1 teaspoon brown sugar and 1 tablespoon vegetable oil in a small bowl and stir to combine a paste.
Preheat oven to 400F degrees.
To prepare the fish, start by wiping the flesh with a dry paper towel to remove any excess moisture.
Rub the blackening paste on one side of the fish.
Pour a small amount of vegetable oil into a large saute pan and heat over medium-high heat. When pan is nice and hot, carefully place fish into preheated pan. Sear on both sides for 2-3 minutes each side. Remove fish from pan and place onto a cookie sheet lined with tinfoil. Place pan into preheated oven and bake for 10-15 minutes or until cod is cooked through.
Remove pan from oven and place fish on top of steamed rice or whatever you’re serving. Top fish with salsa, a lime wedge and extra cilantro.
For Mango salsa, mix 1 mango, red onion, diced red bell pepper, 1/2 jalapeno, and juice of 1 lime, 3 tablespoons fresh cilantro, and salt to taste. Can be made a few hours ahead. Taste just before serving and adjust seasoning as needed.