
In a large wide bowl, combine the ingredients to marinate the chicken; Greek yogurt, olive oil, lemon juice, garlic, oregano, salt, pepper, and chicken thighs. Marinate for at least 30 minutes or overnight.
Heat a grill pan or outdoor grill; add the chicken thighs and cook over medium heat for 4-5 minutes until the chicken is cooked through with beautiful grill marks.
Meanwhile, prepare the salad ingredients and mix them in a large bowl. Add the cooked chicken to the salad and drizzle the prepared dressing over the salad and toss.
Garnish the salad with lemon wedges and serve immediately.