In a small saucepan, bring 0.5 cups of water to a boil, stir in the dry couscous, cover, and remove from heat to let sit for 5 minutes before fluffing with a fork.
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 degrees Fahrenheit.
While the chicken rests, dice the cucumber, halve the cherry tomatoes, and finely mince the red onion and fresh parsley.
In a large mixing bowl, whisk together the extra virgin olive oil, lemon juice, lemon zest, and the remaining salt, pepper, and oregano to create the dressing.
Slice the rested chicken into bite-sized strips or cubes.
Add the fluffed couscous, chopped vegetables, and chicken to the mixing bowl and toss thoroughly until every ingredient is coated in the zesty dressing.
Serve immediately or chill for 30 minutes to allow the flavors to meld together beautifully.