Mediterranean Grilled Chicken Salad

Heat grill to medium-high. Season chicken with coriander, oregano, salt, and pepper. Grill, covered, turning halfway through, until golden and no longer pink, 18 to 22 minutes. Let rest 5 minutes, then slice. Meanwhile, make dressing. Whisk olive oil, red wine vinegar, and parsley in a small bowl and season with salt and pepper. Divide lettuce, cucumbers, tomatoes, avocado, feta, and olives among four serving bowls. Top with sliced chicken, then drizzle with dressing.