Season the chicken breast evenly with half of the sea salt, black pepper, and dried oregano.
Heat a grill pan or cast-iron skillet over medium-high heat and cook the chicken for 6-7 minutes per side until the internal temperature reaches 165°F.
While the chicken is cooking, whisk together the extra virgin olive oil, lemon juice, lemon zest, and the remaining salt, pepper, and oregano in a small bowl to create the dressing.
In a large mixing bowl, combine the cooked quinoa, diced cucumber, halved cherry tomatoes, chopped parsley, and pitted olives.
Once the chicken is finished, let it rest on a cutting board for 5 minutes before slicing it into thin strips or bite-sized pieces.
Add the sliced chicken to the bowl with the quinoa and vegetables.
Drizzle the lemon-herb dressing over the salad and toss thoroughly to ensure everything is well-coated before serving.