Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Chop the broccoli, red bell pepper, and zucchini into uniform bite-sized pieces to ensure even roasting.
Place the vegetables on the baking sheet and toss with 1 tsp of olive oil, half of the sea salt, black pepper, and dried oregano.
Roast the vegetables for 15-20 minutes until they are tender and show slight caramelized charring at the edges.
While the vegetables roast, season the chicken breast evenly with the remaining sea salt, black pepper, garlic powder, and oregano.
Heat the remaining 1 tsp of olive oil in a medium skillet over medium-high heat.
Sear the chicken for 5-7 minutes per side until the internal temperature reaches 165°F and the exterior is golden brown.
Remove the chicken from the pan and let it rest for 3 minutes before slicing into thin strips.
In a serving bowl, combine the roasted vegetables and sliced chicken over the warm cooked quinoa.
Drizzle with fresh lemon juice to brighten the flavors and serve immediately.