Add all the spices to a small bowl and use a fork to stir together until evenly incorporated. Evenly divide the spices between the pieces of fish and use your hands to gently rub/press them into both sides. Liberally salt and pepper the fillets.
1 tbsp chili powder, 1 tbsp cumin, 1/2 tsp cayenne pepper, 1/2 tsp smoked paprika, 1/4 tsp onion powder, scant 1/8 tsp oregano, lime zest, 4 tilapia filets
Drizzle a large cast iron skillet, or dutch oven, liberally with olive oil and heat over medium high heat. When the oil's hot quickly add in the garlic and saute while stirring for about 20 seconds.
3 cloves garlic
Working in batches of two, add in the fish fillets. Let the fish cook undisturbed for about 2-3 minutes so it develops a nice deep sear, almost char-like. Use a spatula to carefully flip the fish over and continue cooking on the other side for 2 minutes. When the fish is completely cooked through use a spatula to transfer the fillets to a platter. Repeat this with the second batch, adding more olive oil before continuing.
Transfer the second batch of cooked fillets to the same platter and sprinkle each filet with a bit of lime zest.
Use the same, now empty skillet and add a bit more olive oil. Stir in the corn and red bell pepper. Cook for 1-2 minutes without stirring, then stir and continue cooking for a few more minutes, or until the veggies are tender.
1 cup cooked corn kernels, 1 red bell pepper
Add in the black beans and stir to evenly incorporate, and cook just until heated through. Remove the skillet from heat, and set aside.
1 can black beans
Add 1/2 cup cilantro lime rice to a bowl and top with some of the veggie mixture, pieces of blackened fish, and any/all of the assorted toppings.
2 cups cooked cilantro lime rice