Season the chicken breast evenly with half of the sea salt, black pepper, and dried oregano.
Grill the chicken over medium-high heat for approximately 6-7 minutes per side until the internal temperature reaches 165°F.
Remove the chicken from the heat and let it rest for 5 minutes before dicing into bite-sized cubes.
In a large mixing bowl, whisk together the extra virgin olive oil, lemon juice, and the remaining sea salt, black pepper, and dried oregano to create the vinaigrette.
Add the diced chicken, chickpeas, cucumber, cherry tomatoes, and red onion to the bowl with the dressing.
Toss all ingredients thoroughly to ensure everything is well-coated in the lemon-herb mixture.
Transfer to a serving plate and garnish with crumbled feta cheese and freshly chopped parsley.