Add chicken to a mixing bowl.
Add olive oil, lemon juice, Cavender's Greek Seasoning, garlic powder, black pepper, and oregano.
Massage thoroughly to coat.
Marinate for 20 to 30 minutes.
Rinse the quinoa thoroughly.
Add quinoa and water to a medium saucepan.
Bring to a boil.
Reduce heat, cover, and cook for 15 minutes.
Turn off the heat and let rest covered for 5 minutes.
Fluff with a fork and allow to cool slightly.
Halve the cherry tomatoes.
Dice the cucumber.
Thinly slice the red onion.
Chop the parsley.
Slice the olives if desired.
Add the cooled quinoa, tomatoes, cucumber, red onion, olives, and parsley to a large mixing bowl.
Mix gently.
In a small bowl, whisk together olive oil, balsamic vinegar, Cavender's Greek Seasoning, and black pepper.
Pour the dressing over the quinoa mixture and toss gently to combine.
Preheat a grill or grill pan over medium high heat.
Cook the chicken for 5 to 7 minutes per side until grill marks develop and the internal temperature reaches 165 degrees.
Remove from heat and allow to rest for 5 minutes.
Slice the chicken against the grain.
Plate the quinoa salad and top with sliced grilled chicken.
Serve immediately.