Season the chicken: Warm a skillet over medium heat with the oil. Add the cooked chicken and sprinkle with taco seasoning. Stir until the chicken is coated and fragrant, 2–3 minutes.
If it looks dry, add a splash of water. Set aside to cool slightly.
Mix the dressing: In a small bowl, whisk Greek yogurt, salsa, lime juice, cumin, garlic powder, a pinch of salt, and black pepper. Adjust thickness with a teaspoon of water if needed.
Taste and add more lime or salt to brighten.
Prep the veggies: Chop greens, halve tomatoes, dice the bell pepper and red onion, and rinse the black beans. If using corn, lightly char it in a dry skillet for a few minutes for extra flavor.
Assemble the base: In a large bowl or on a platter, layer greens, tomatoes, corn, black beans, bell pepper, and red onion.
Add the chicken: Scatter the warm taco chicken over the veggies. Warmth helps release aromas and softens the greens slightly without wilting too much.
Dress it up: Drizzle half the dressing over the salad and toss gently to coat.
Add the avocado and cilantro, then drizzle a bit more dressing. Keep some on the side for serving.
Finish and serve: Top with optional tortilla strips for crunch, a sprinkle of cotija, and extra lime wedges. Serve right away.