Pat the chicken thighs dry with paper towels. Season both sides with kosher salt and black pepper.
Heat olive oil in a large skillet over medium-high heat. Add the chicken thighs skin-side down and cook until the skin is golden brown and crispy, about 6-7 minutes. Flip and cook for another 4 minutes. Remove the chicken from the skillet and set aside.
Reduce heat to medium. Add the chopped onion to the skillet and sauté until softened and translucent, about 4 minutes.
Add the minced garlic and cook for 30 seconds until fragrant.
Add the rinsed rice to the skillet and stir to coat the rice with the oil, onion, and garlic mixture. Cook for 1-2 minutes to lightly toast the rice.
Pour in the chicken broth, lemon zest, lemon juice, dried oregano, ground cumin, and crushed red pepper flakes. Stir to combine.
Return the chicken thighs to the skillet, placing them skin-side up on top of the rice mixture.
Bring the liquid to a simmer, then reduce heat to low. Cover the skillet with a tight-fitting lid and cook for 25 minutes, or until the rice is tender and the chicken is cooked through (internal temperature should reach 165°F).
Remove the skillet from heat and let it rest, covered, for 5 minutes.
Sprinkle chopped fresh parsley over the dish before serving.