Preheat your oven to 400°F and line a baking sheet with parchment paper.
Dice the zucchini, red bell pepper, and red onion into uniform bite-sized pieces.
Toss the vegetables on the baking sheet with 0.25 tablespoons of olive oil and a pinch of sea salt and black pepper.
Roast the vegetables for 20 minutes until they are tender and show slight caramelization at the edges.
While vegetables roast, rinse the quinoa under cold water and combine it with the water in a small saucepan.
Bring the quinoa to a boil, then reduce heat to low, cover, and simmer for 15 minutes until the water is absorbed.
Season the chicken breast evenly with garlic powder and the remaining sea salt and black pepper.
Heat the remaining 0.5 tablespoons of olive oil in a skillet over medium-high heat and sear the chicken for 6 to 7 minutes per side until cooked through.
Remove the chicken from the pan and let it rest for 3 minutes before slicing into strips.
Fluff the cooked quinoa with a fork and gently fold in the roasted vegetables, lemon juice, and chopped fresh parsley.
Transfer the quinoa pilaf to a plate and top with the sliced pan-seared chicken breast.