Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Dice the chicken breast, eggplant, zucchini, and red bell pepper into uniform 1-inch cubes, and thinly slice the red onion.
In a large mixing bowl, combine the chicken and chopped vegetables with extra virgin olive oil, garlic powder, dried oregano, sea salt, and black pepper.
Toss everything thoroughly until the chicken and vegetables are evenly coated in oil and spices.
Spread the mixture in a single layer on the prepared baking sheet, ensuring enough space for roasting rather than steaming.
Roast in the oven for 20 to 25 minutes, or until the chicken is cooked through and the vegetables are tender with slightly caramelized edges.
While the vegetables roast, add the crushed tomatoes and lemon zest to a small saucepan and simmer over low heat for 5 minutes.
Remove the sheet pan from the oven and transfer the roasted chicken and vegetables into a serving bowl.
Pour the warm, zesty tomato sauce over the mixture and toss gently to combine.
Garnish with freshly torn basil leaves before serving.