Season the chicken breast with half of the sea salt, black pepper, and dried oregano.
Heat a non-stick skillet over medium-high heat and sauté the chicken for 6-7 minutes per side until the internal temperature reaches 165°F.
Remove the chicken from the pan and let it rest for 5 minutes before dicing it into small cubes.
In a large mixing bowl, combine the cooked green lentils, diced cucumber, halved cherry tomatoes, and minced red onion.
Add the diced chicken to the bowl with the vegetable and lentil mixture.
Whisk together the extra virgin olive oil and lemon juice in a small ramekin, then pour it over the salad.
Add the remaining sea salt, black pepper, and oregano, then toss all ingredients together until evenly coated.
Top the salad with crumbled feta cheese and chopped fresh parsley before serving.