In a small bowl, combine the olive oil, lemon juice, black pepper, garlic powder, and salt. Whisk until well blended. Place the chicken breasts in a resealable bag or shallow dish, and pour the marinade over them. Seal or cover, then refrigerate for 30 minutes to marinate.
Heat a large skillet over medium-high heat. Once hot, add a small amount of olive oil to the pan (or spray with cooking spray). If grilling, preheat the grill to medium-high heat.
Remove the chicken from the marinade, allowing excess liquid to drip off. Cook the chicken for 6-8 minutes on each side, or until the internal temperature reaches 165°F and the chicken is golden brown.
Remove the chicken from the skillet or grill and let it rest for 5 minutes to allow the juices to redistribute.
Garnish the chicken with fresh parsley and serve with lemon wedges for extra zing.