Season the chicken breast evenly with half of the sea salt, black pepper, and dried oregano.
Heat a non-stick skillet over medium-high heat and cook the chicken for 6-7 minutes per side until golden brown and cooked through.
While the chicken is cooking, dice the cucumber, halve the cherry tomatoes, and finely mince the red onion.
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 dressing.
Once the chicken is finished, let it rest for 2 minutes before slicing it into thin strips.
Add the cooked quinoa, diced cucumber, halved tomatoes, minced onion, and kalamata olives to the bowl with the dressing.
Toss the salad thoroughly to ensure even coating, then top with the crumbled feta cheese and the sliced chicken before serving.