Marinate the chicken: In a bowl, combine olive oil, lemon juice, minced garlic, dried oregano, salt, and pepper. Coat the chicken with the marinade and let it sit for at least 30 minutes.
Cook the orzo: Bring a pot of salted water to a boil. Cook the orzo according to package instructions. Drain and set aside.
Grill the chicken: Heat a grill or grill pan over medium-high heat. Grill the chicken for 6-7 minutes on each side until fully cooked. Let it rest before slicing.
Assemble the bowl: In a large bowl, combine the cooked orzo, cherry tomatoes, cucumber, olives, red onion, feta, and parsley.
Serve: Top the orzo mixture with the grilled chicken slices. Drizzle with extra olive oil and lemon juice if desired. Enjoy!