Grill or pan-cook the chicken breast until fully cooked, about 20 minutes. Let it cool, then shred or dice.

In a large mixing bowl, combine the cooked chicken, cherry tomatoes, cucumber, bell pepper, and spinach.

In a small bowl, whisk together olive oil, Greek yogurt, lemon juice, honey, salt, and black pepper until smooth.

Pour the dressing over the salad and toss to combine. Top with feta cheese and walnuts before serving.