Preheat your oven to 400°F (200°C) and line a small baking sheet with parchment paper.
Dice the zucchini and red bell pepper into bite-sized pieces and place them on the baking sheet.
Toss the vegetables with half of the olive oil, a pinch of sea salt, and black pepper.
Roast the vegetables for 15 to 20 minutes until they are tender and show light golden edges.
While the vegetables roast, season the chicken breast with the dried oregano and the remaining sea salt and pepper.
Heat the remaining olive oil in a skillet over medium heat and sear the chicken until fully cooked through, about 6 minutes per side.
Let the chicken rest for 3 minutes before slicing it into thin strips.
Place the warm cooked quinoa in the bottom of a serving bowl.
Arrange the roasted vegetables and sliced chicken on top of the quinoa.
Finish the bowl by sprinkling with crumbled feta cheese and drizzling with fresh lemon juice.