Season the chicken thighs with salt and black pepper on both sides.
Heat olive oil in a large deep skillet or Dutch oven over medium-high heat.
Add the chicken thighs skin side down and cook for 5-7 minutes until the skin is golden brown and crispy. Flip and cook for another 3 minutes. Remove chicken from the skillet and set aside.
Reduce heat to medium. Add the chopped onion to the same skillet and sauté for 3-4 minutes until translucent.
Add the minced garlic and cook for 30 seconds until fragrant.
Add the rinsed rice to the skillet and stir to coat the rice in the oil and onion mixture.
Pour in the chicken broth, lemon zest, lemon juice, dried oregano, and crushed red pepper flakes. Stir to combine.
Return the chicken thighs to the skillet, placing them on top of the rice mixture, skin side up.
Bring the mixture to a boil, then reduce heat to low. Cover and simmer for 25 minutes, or until the rice is tender and the chicken is cooked through (internal temperature of 165°F).
Remove the skillet from heat and let it sit, covered, for 5 minutes.
Sprinkle chopped fresh parsley over the dish before serving.