In a medium saucepan, combine the dry quinoa with 0.66 cups of water and a pinch of salt. Bring to a boil, then reduce heat to low, cover, and simmer for 15 minutes or until water is absorbed. Fluff with a fork and set aside.
While the quinoa cooks, mince the garlic and whisk it in a small bowl with the dried oregano, sea salt, black pepper, and half of the olive oil to create a marinade. Coat the chicken breast thoroughly with the herb mixture.
Heat the remaining olive oil in a large skillet over medium-high heat. Place the chicken in the pan and sear for 6 to 7 minutes per side until the exterior is golden brown and the internal temperature reaches 165°F. Remove from heat and let rest for 5 minutes before slicing.
Prepare the fresh components by dicing the cucumber, halving the cherry tomatoes, and mincing the red onion.
To assemble, divide the cooked quinoa into a bowl or meal prep containers for leftovers. Top with the sliced herb chicken, cucumber, tomatoes, red onion, and kalamata olives.
Finish the bowl by drizzling with fresh lemon juice and topping with crumbled feta cheese and a dollop of hummus.