Prepare the Blackened Tilapia:
- In a small bowl, combine smoked paprika, garlic powder, onion powder, cumin, cayenne (if using), salt, and black pepper.
- Pat the tilapia fillets dry with a paper towel and coat both sides with olive oil. Rub the spice mixture evenly over both sides of each fillet.
- Heat a large non-stick skillet over medium-high heat. Add a little olive oil if needed. Cook the fillets for 3-4 minutes per side, or until the fish is opaque and flakes easily with a fork. Remove from heat and let rest for a few minutes before breaking into large chunks.
Make the Avocado Cilantro Sauce:
- In a blender or food processor, combine avocado, Greek yogurt, lime juice, garlic, cilantro, olive oil, and salt. Blend until smooth.
- Add water, 1 tablespoon at a time, until the sauce reaches your desired consistency.
Assemble the Tacos:
- Place a layer of shredded red cabbage on each tortilla.
- Top with chunks of blackened tilapia, a drizzle of avocado cilantro sauce, diced onion, and chopped cilantro.
- Serve with lime wedges for squeezing over the top.