Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Cut the chicken breast into 1-inch cubes and place them in a large mixing bowl.
Slice the zucchini into half-moons, chop the red bell pepper into 1-inch pieces, and thinly slice the red onion.
Add the vegetables to the bowl with the chicken, then drizzle with the extra virgin olive oil.
Sprinkle the dried oregano, garlic powder, sea salt, and black pepper over the mixture and toss thoroughly to coat every piece.
Spread the chicken and vegetables in a single layer on the prepared baking sheet, ensuring they are not overcrowded.
Roast in the oven for 20 to 25 minutes, or until the chicken is cooked through and the vegetables are tender and slightly caramelized.
Remove from the oven, drizzle with fresh lemon juice, and top with crumbled feta cheese before serving.