Preheat your grill to medium-high heat.
In a small bowl, mix garlic powder, onion powder, salt, pepper, and Parmesan cheese.
Brush chicken breasts with olive oil on both sides.
Rub the spice and cheese mixture evenly over the chicken.
Grill chicken for 5-7 minutes per side or until the internal temperature reaches 165°F (75°C).
Garnish with chopped parsley before serving if desired.