Heat olive oil in a large skillet or saucepan over medium heat.
Add the chopped onion and sauté for 3-4 minutes until translucent.
Add the minced garlic and cook for an additional 1 minute until fragrant.
Add the chicken pieces to the skillet and cook for 5-6 minutes, stirring occasionally, until the chicken is lightly browned on all sides but not fully cooked through.
Add the rinsed rice to the skillet and stir to combine with the chicken and onions.
Pour in the chicken broth, then add the dried oregano, black pepper, and salt. Stir well.
Bring the mixture to a boil, then reduce heat to low, cover, and simmer for 15 minutes.
After 15 minutes, stir in the frozen peas, cover again, and cook for an additional 5 minutes until the rice is tender and the chicken is fully cooked.
Remove from heat and let stand, covered, for 5 minutes.
Fluff the rice with a fork and stir in the chopped fresh parsley before serving.