Preheat your grill or stovetop grill pan over medium heat.
In a bowl, mix olive oil, lemon juice, oregano, salt, and pepper.
Coat the chicken breasts in the marinade and let sit for 10 minutes.
Grill the chicken for 6-7 minutes on each side or until cooked through.
While the chicken is grilling, prepare the salad base with mixed greens.
Slice the grilled chicken into strips once cooked.
Arrange the sliced chicken on top of the mixed greens.
Add cherry tomatoes, cucumber, feta, and olives to the bowl.
Drizzle with any remaining marinade for added flavor.
Serve immediately and enjoy your Greek chicken bowl!