In a medium bowl, add olive oil, lemon juice, oregano, rosemary, garlic, salt and pepper. Whisk with a fork.
Add chicken to the bowl, poking and tossing with a fork. This will allow marinade to penetrate the meat. Cover and refrigerate for 30 minutes to 48 hours. The longer you marinate, the deeper the flavor.
To pan fry: Preheat large ceramic non-stick skillet on medium heat and swirl a bit of oil to coat. Add chicken, cover and cook for 5-6 minutes. Flip and cook for another 5-6 minutes or until the thickest part juices run clear when poked with a knife or fork.
To grill: Preheat grill on medium-high (450-500 degrees F) and rub with oiled paper towel. Place chicken on the grill, close the lid and grill for 8-10 minutes turning once. Do not overcook.
To bake: Preheat oven to 450 degrees F. Rub bottom of large baking dish with oil and lay chicken breasts in a single layer. Bake uncovered for 25 minutes for thinner pieces to 35 minutes for 2 inches plus, or until 150 degrees F internal temperature.
For all methods: Discard marinade. Make sure you let chicken rest. Place cooked chicken into a baking dish, cover with foil and let rest for 5 minutes. This step helps juices settle back into the meat.
Notes
Store marinade: Once prepared and mixed, the marinade will last, covered, in the refrigerator for up to a week.
Store chicken leftovers: Cool chicken and refrigerate in an airtight container for 3-4 days.
Freeze: Freeze for up to 3 months.
Freezer meal prep: Combine the raw chicken and marinade and freeze immediately. A day before you wish to eat it, defrost the chicken in the fridge. During this time, it will marinate and can be cooked once fully thawed.
Don't re-use the marinade: Unless you boil it first.