Bring a medium pot of salted water to a boil and cook the orzo until al dente, then drain and rinse with cold water to stop the cooking process.
Season the chicken breast evenly with garlic powder, half of the dried oregano, sea salt, and black pepper.
Heat a skillet or grill pan over medium-high heat and cook the chicken for 6 to 7 minutes per side until fully cooked through.
Transfer the chicken to a cutting board and allow it to rest for 5 minutes before dicing into small cubes.
In a large bowl, whisk together the olive oil, lemon juice, and the remaining dried oregano to create the dressing.
Add the cooled orzo, diced chicken, cucumber, cherry tomatoes, and red onion to the bowl with the dressing.
Toss the ingredients thoroughly until every component is well-coated in the vinaigrette.
Garnish the salad with crumbled feta cheese and freshly chopped parsley before serving.