Preheat your oven to 400°F and line a large baking sheet with parchment paper for easy cleanup.
Toss the broccoli florets, diced red bell pepper, and red onion with 1 teaspoon of olive oil and a pinch of sea salt on the prepared baking sheet.
Roast the vegetables for 18 to 20 minutes until they are tender and show slight caramelized charring on the edges.
While vegetables roast, rinse the quinoa in a fine-mesh strainer and combine it with the chicken broth in a small saucepan.
Bring the broth to a boil, then reduce heat to low, cover, and simmer for 15 minutes until the liquid is fully absorbed.
Season the chicken breast evenly on both sides with the garlic powder, black pepper, and remaining sea salt.
Heat the remaining 1 teaspoon of olive oil in a skillet over medium-high heat and sear the chicken for 6 minutes per side until golden and cooked through.
Remove the chicken from the pan and let it rest for 3 minutes before slicing it into thin strips.
Fluff the cooked quinoa with a fork and gently fold in the roasted vegetables, fresh parsley, and lemon juice.
Plate the vegetable quinoa pilaf and top with the sliced chicken breast to serve immediately.