In a large mixing bowl, combine the olive oil, lemon zest, lemon juice, minced garlic, chopped onion, dried oregano, dried thyme, paprika, salt, and pepper. Whisk everything together until well blended. This mixture will double as both the marinade for the chicken and the flavor base for the rice.
Add the chicken breasts to the marinade, ensuring they are fully coated. Let them sit for at least 15 minutes at room temperature, or for more flavor, cover and refrigerate for up to 2 hours.
Pour the uncooked rice into the baking dish. Pour the chicken broth over the rice, then stir in the frozen peas. Spread the rice and peas evenly in the dish, creating a bed for the chicken.
Remove the chicken breasts from the marinade (reserve the marinade) and place them gently on top of the rice layer. Pour the reserved marinade evenly over the chicken and rice to boost flavor and moisture.
Preheat your oven to 375°F (190°C). Cover the baking dish with aluminum foil to keep the moisture locked in, and bake for 35 minutes. After 35 minutes, remove the foil and bake for an additional 10-15 minutes, or until the chicken is cooked through and the rice is tender.
Once out of the oven, sprinkle the freshly chopped parsley over the dish to add a burst of color and fresh flavor. Let the dish rest for 5 minutes before serving.