Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Cut the chicken breast into uniform 1-inch bite-sized pieces to ensure even cooking.
Dice the zucchini into half-moons, chop the red bell pepper into 1-inch squares, and break the broccoli into small florets.
Place the chicken and all the vegetables onto the prepared baking sheet and drizzle with the extra virgin olive oil.
Sprinkle the sea salt, black pepper, garlic powder, and dried oregano evenly over the mixture.
Use your hands or a spatula to toss everything together until the chicken and vegetables are thoroughly coated in oil and spices.
Spread the mixture out into a single layer, ensuring there is space between the pieces so they roast rather than steam.
Roast in the center of the oven for 20 to 25 minutes, or until the chicken is cooked through and the vegetables are tender with slightly charred edges.
Remove the pan from the oven and immediately drizzle the fresh lemon juice over the hot medley to brighten the flavors.
Serve immediately while warm and fragrant.