In a small bowl, mix together the smoked paprika, garlic powder, onion powder, cayenne pepper, oregano, salt, and black pepper. Rub the spice mixture evenly over both sides of the fish fillets.

Heat the olive oil in a large skillet over medium-high heat. Once hot, add the fish fillets and cook for about 3-4 minutes on each side, or until the fish is cooked through and has a blackened crust. Remove from the skillet and let rest for a few minutes before flaking into bite-sized pieces.

In serving bowls, layer the cooked brown rice or quinoa as the base. Top with blackened fish, cherry tomatoes, corn, avocado, red cabbage, and cilantro.

Serve with lime wedges on the side and a dollop of sour cream or Greek yogurt if desired.