Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Dice the sweet potato into 1/2-inch cubes and chop the bell pepper and zucchini into bite-sized pieces.
Cut the chicken breast into 1-inch chunks to ensure even cooking with the vegetables.
In a large bowl, whisk together the olive oil, garlic powder, dried oregano, sea salt, and black pepper.
Add the chicken, sweet potatoes, broccoli, peppers, and zucchini to the bowl and toss until everything is thoroughly coated in the herb oil.
Spread the mixture in a single layer on the prepared baking sheet, ensuring nothing is overcrowded.
Roast for 20-25 minutes, tossing halfway through, until the chicken is cooked through and the vegetables are tender and slightly caramelized.
Remove from the oven and drizzle with fresh lemon juice before serving.