1. In a medium mixing bowl, combine the Greek yogurt, olive oil, lemon juice, minced garlic, dried oregano, paprika, salt, black pepper, and lemon zest. Whisk the ingredients together until well blended and smooth, creating a flavorful marinade.

2. Place the chicken breasts in a large resealable plastic bag or shallow dish. Pour the yogurt marinade over the chicken, ensuring that each piece is thoroughly coated. Seal the bag or cover the dish with plastic wrap.

3. Refrigerate the marinating chicken for at least 1 hour, but ideally for 4 to 8 hours. This allows the flavors to penetrate the chicken and keeps it moist during cooking.

4. Preheat your grill or oven to a medium-high heat (about 375°F or 190°C). If using a grill, oil the grates to prevent sticking.

5. Remove the chicken from the marinade, letting excess marinade drip off. Discard the remaining marinade.

6. If grilling, place the chicken breasts on the grill and cook for about 6-7 minutes per side, or until the internal temperature reaches 165°F (75°C) and the chicken is cooked through. If baking, place the chicken on a baking sheet lined with parchment paper and bake for 25-30 minutes, or until fully cooked.

7. Once cooked, let the chicken rest for 5 minutes before slicing. This helps retain the juices for a more tender bite.

8. If desired, garnish with freshly chopped parsley before serving. Serve alongside your favorite sides, such as roasted vegetables, rice, or a salad.