Begin by cutting the chicken breasts into bite-sized pieces and place them in a mixing bowl.
In a separate bowl, whisk together olive oil, minced garlic, lemon juice, lemon zest, dried oregano, salt, and black pepper until well combined.
Pour the marinade over the chicken pieces, ensuring all the chicken is evenly coated. Cover the bowl and let it marinate for at least 10 minutes (or up to 1 hour in the refrigerator for better flavor).
Heat a skillet over medium-high heat and add the marinated chicken.
Cook the chicken for about 6-8 minutes, stirring occasionally, until it is golden brown, cooked through, and reaches an internal temperature of 165°F (75°C).
Once cooked, remove the skillet from heat and let the chicken rest for a couple of minutes.
Garnish with chopped parsley and serve immediately, either on its own or with a side of your choice.