Combine paprika, garlic powder, oregano, onion powder, chili powder, cumin, salt, cayenne, and brown sugar in a small bowl. If you happen to have some smoked salt, add a pinch but I don’t think I would buy it JUST for this recipe.
Once combined, sprinkle spice mix on both sides of tilapia filets. Use a liberal hand. It should cover most of the fish.
Heat a large skillet (cast iron or nonstick) over medium-high heat and add a drizzle of oil. Once the oil is hot, add fish filets and cook for 3-4 minutes per side until the fish is blackened around the edges and flakes apart easily.
Keep fish warm until serving.
For slaw: Grate radishes and carrots and toss together with sliced onion and lime juice. Season with salt and pepper. It’s best to let the slaw sit for 10-15 minutes if possible. Drain off any liquid before making tacos.
For avocado cream: Combine ingredients in a small food processor and pulse until smooth. You can also mash up avocado and stir in ingredients for a slightly chunkier version.
Warm tortilla in a 250 degree oven and serve fish in tacos with slaw and cream sauce. Garnish the tacos with fresh cilantro and crumbled cotija cheese.