In a large mixing bowl, whisk together Greek yogurt, olive oil, lemon juice and zest, minced garlic, oregano, and salt and pepper until smooth and creamy.

Add chicken tenders to the marinade, ensuring each piece is well coated. Cover with plastic wrap and refrigerate for at least 30 minutes.

Preheat grill pan over medium heat or set oven to 400°F (200°C).

Remove chicken from marinade and cook on grill for 5-7 minutes on each side until golden brown and cooked through.

Let the chicken tenders rest for about 5 minutes before serving.