Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
Toss the broccoli florets and sliced red bell peppers with half of the olive oil, a pinch of sea salt, and black pepper.
Spread the vegetables in a single layer on the baking sheet and roast for 15-20 minutes until the broccoli edges are crispy and charred.
While the vegetables roast, season the chicken breast on both sides with dried oregano, garlic powder, sea salt, and black pepper.
Heat the remaining olive oil in a medium skillet over medium-high heat.
Place the chicken in the skillet and sear for 6-7 minutes per side, or until the internal temperature reaches 165°F.
During the last minute of cooking, pour the lemon juice into the pan to deglaze and coat the chicken.
Fluff the pre-cooked quinoa and place it in a bowl.
Top the quinoa with the pan-seared chicken and the roasted vegetables to serve.