In a small bowl, whisk together half of the lemon juice, dried oregano, sea salt, and black pepper.
Coat the chicken breast thoroughly with the lemon-herb mixture and let it marinate for 5 minutes.
Heat the extra virgin olive oil in a skillet over medium-high heat until shimmering.
Place the chicken in the skillet and sear for 6 to 8 minutes per side until the exterior is golden brown and the internal temperature reaches 165°F.
Remove the chicken from the pan and let it rest on a cutting board for 3 minutes before slicing into thin strips.
In the same skillet, add the minced garlic and sliced zucchini, sautéing for 3 to 4 minutes until tender-crisp and lightly browned.
In a serving bowl, fluff the warm cooked quinoa and toss it with the remaining lemon juice and fresh lemon zest.
Top the quinoa with the sautéed zucchini and the sliced lemon-herb chicken.
Finish the bowl by sprinkling the crumbled feta cheese over the top for a bright and tangy finish.