Season the chicken breast with half of the sea salt, black pepper, and dried oregano.
Heat a non-stick skillet over medium heat and cook the chicken for 6-7 minutes per side until the internal temperature reaches 165°F and the exterior is golden.
While the chicken is cooking, dice the cucumber and red onion, and halve the cherry tomatoes.
In a small glass jar or bowl, whisk together the extra virgin olive oil, fresh lemon juice, and the remaining sea salt, black pepper, and dried oregano to create the dressing.
Once the chicken is cooked, let it rest for 3 minutes before slicing it into bite-sized strips.
In a large salad bowl, combine the chopped cucumber, cherry tomatoes, red onion, and Kalamata olives.
Add the sliced chicken and crumbled feta cheese to the bowl.
Drizzle the lemon vinaigrette over the salad and toss gently to ensure every ingredient is lightly coated before serving.