In a mixing bowl, combine the olive oil, lemon juice, minced garlic, oregano, thyme, salt, black pepper, and red pepper flakes (if using). Whisk until well blended.
Place the chicken breasts in a Ziplock bag or shallow dish and pour the marinade over them. Ensure the chicken is fully coated. Seal the bag or cover the dish.
Refrigerate and marinate for at least 30 minutes or up to 2 hours for more flavor.
Preheat your grill, oven, or skillet while the chicken is marinating. For grilling, heat to medium-high; for a skillet, heat over medium heat; and for the oven, preheat to 400°F (200°C).
Remove the chicken from the marinade, letting excess drip off. Discard the remaining marinade.
Cook the chicken using your chosen method: on the grill, cook for 6-7 minutes per side or until fully cooked (internal temperature of 165°F/75°C); in the oven, bake for 20-25 minutes or until fully cooked; or in a skillet, cook for about 5-7 minutes per side until fully cooked.
Let the chicken rest for a few minutes before slicing. Serve it hot, garnished with fresh herbs if desired.