Preheat oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Chop the zucchini into half-moons, slice the bell pepper into bite-sized strips, and mince the garlic.
Cut the chicken breast into 1-inch cubes to ensure even cooking and maximum surface area for seasoning.
In a large bowl, toss the chicken, zucchini, bell peppers, and cherry tomatoes with olive oil, minced garlic, dried oregano, sea salt, and black pepper.
Spread the mixture in a single layer on the prepared baking sheet, ensuring nothing is overcrowded so the vegetables roast rather than steam.
Roast for 18-22 minutes, or until the chicken is cooked through and the vegetables are tender with slightly charred edges.
Remove from the oven, drizzle with fresh lemon juice, and garnish with chopped parsley before serving.