Season the chicken breast evenly with half of the sea salt, black pepper, and dried oregano.
Heat a skillet over medium-high heat with a small portion of the olive oil and sear the chicken for 6-7 minutes per side until fully cooked.
Remove the chicken from the heat, let it rest for 5 minutes, then slice into thin strips or cubes.
In a large mixing bowl, whisk together the remaining olive oil, lemon juice, minced garlic, and the rest of the salt, pepper, and oregano.
Add the cooked quinoa, diced cucumber, halved cherry tomatoes, and chopped parsley to the bowl.
Toss the ingredients thoroughly until the quinoa and vegetables are well-coated in the dressing.
Fold in the sliced chicken or serve it on top of the salad for a clean, protein-packed lunch.