Preheat your oven to 400°F and line a large sheet pan with parchment paper for easy cleanup.
Dice the sweet potato into small 1/2-inch cubes and slice the zucchini into half-moons.
In a large mixing bowl, combine the chicken breast, sweet potato cubes, broccoli florets, and zucchini.
Drizzle with olive oil and sprinkle with dried oregano, garlic powder, sea salt, and black pepper, tossing until everything is evenly coated.
Spread the chicken and vegetables in a single layer on the prepared baking sheet, ensuring they are not overcrowded to allow for even browning.
Roast for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the sweet potatoes are tender.
Remove from the oven and immediately finish with a bright drizzle of lemon juice and a sprinkle of fresh lemon zest before serving.