- In a large mixing bowl, combine the cooked chicken, diced cucumber, cherry tomatoes, and red onion. 
- In a separate small bowl, whisk together the Greek yogurt, mayonnaise, Dijon mustard, dill, lemon juice, salt, and pepper until smooth. 
- Pour the dressing over the chicken and vegetable mixture. Gently toss until everything is well coated. 
- Taste and adjust seasoning if necessary. If the salad is too thick, you can add a little more lemon juice or a splash of water to reach your desired consistency. 
- Serve the salad on a bed of lettuce leaves if desired, or enjoy it on its own.