Preheat your oven to 425°F (220°C).
In a large bowl, combine the Greek yogurt, zaatar, olive oil, minced garlic, salt, pepper, and lemon juice. Mix well to create a marinade.
Add the chicken thighs to the bowl, ensuring they are fully coated with the marinade. Cover and refrigerate for at least 1 hour, or up to overnight for more flavor.
Arrange the marinated chicken thighs in a single layer on a baking sheet lined with parchment paper.
Bake in the preheated oven for 35-40 minutes, or until the chicken is cooked through and the skin is crispy. An internal temperature of 165°F (74°C) should be reached.
Remove from the oven and let rest for 5 minutes. Garnish with fresh parsley before serving.