Heat the olive oil in a large skillet over medium-high heat.
Add the diced chicken breast to the skillet and cook for 5-6 minutes until golden brown and cooked through.
Stir in the diced red onion and sliced bell peppers, sautéing for 3-4 minutes until the vegetables are tender-crisp.
Add the rinsed black beans, chili powder, cumin, garlic powder, sea salt, and black pepper to the pan.
Cook for an additional 2 minutes, stirring frequently to combine the spices and heat the beans.
While the filling finishes, warm the corn tortillas in a dry pan or over a low open flame for 30 seconds per side until pliable.
Divide the chicken and bean mixture evenly among the three warm tortillas.
Top each taco with fresh avocado slices, a squeeze of lime juice, and a sprinkle of chopped cilantro before serving.