Season the chicken breast with half of the sea salt, black pepper, and dried oregano.
Heat a grill pan or skillet over medium-high heat and cook the chicken for 6-7 minutes per side until the internal temperature reaches 165°F.
Transfer the chicken to a cutting board and let it rest for 5 minutes before slicing into bite-sized cubes.
In a small jar or bowl, whisk together the extra virgin olive oil, fresh lemon juice, minced garlic, and the remaining salt, pepper, and oregano to create the vinaigrette.
In a large bowl or portable container, combine the cooked quinoa, diced cucumber, halved cherry tomatoes, and chopped fresh parsley.
Add the sliced chicken to the salad and drizzle with the lemon-herb vinaigrette.
Toss gently to ensure all ingredients are evenly coated and store in the refrigerator until ready to enjoy.