01 - Whisk together Greek yogurt, minced garlic, lemon juice, olive oil, oregano, cumin, smoked paprika, salt, black pepper, and lemon zest in a large bowl until fully combined.
02 - Add chicken breasts to the bowl and turn to coat thoroughly with the marinade. Cover and refrigerate for at least 2 hours, up to 8 hours for maximum flavor absorption.
03 - Preheat grill to medium-high heat or preheat oven to 425°F.
04 - Take chicken out of the marinade and allow excess to drip off. Discard any remaining used marinade.
05 - Grill chicken for 6 to 8 minutes per side until internal temperature reaches 165°F, or bake on a lined baking sheet for 18 to 22 minutes until cooked through.
06 - Let chicken rest for 5 minutes before slicing. Garnish with chopped fresh parsley and serve with lemon wedges on the side.