Preheat the oven to 400°F (200°C).
In a medium saucepan, combine the rinsed quinoa and chicken broth. Bring to a boil over medium-high heat, then reduce to a simmer, cover, and cook for 15 minutes or until the quinoa is tender and the liquid is absorbed. Remove from heat and fluff with a fork.
While the quinoa cooks, heat olive oil in a large oven-safe skillet over medium-high heat.
Season the chicken breasts evenly with salt, black pepper, and dried oregano on both sides.
Add the chicken breasts to the skillet and sear for 3-4 minutes on each side until golden brown.
Add the minced garlic to the skillet and cook for 1 minute until fragrant.
Stir in the lemon zest and lemon juice, then spoon the cooked quinoa evenly around the chicken breasts in the skillet.
Transfer the skillet to the preheated oven and bake for 12-15 minutes, or until the chicken reaches an internal temperature of 165°F (74°C).
Remove the skillet from the oven and sprinkle the crumbled feta cheese and chopped fresh parsley over the chicken and quinoa.
Let rest for 5 minutes before serving.