Preheat your oven to 400°F and line a large baking sheet with parchment paper.
Dice the chicken breast, zucchini, eggplant, red bell pepper, and red onion into uniform bite-sized pieces.
In a large mixing bowl, combine the diced chicken and vegetables with olive oil, dried oregano, sea salt, black pepper, and minced garlic.
Toss everything thoroughly until the ingredients are evenly coated in the oil and spices.
Spread the mixture in a single layer across the prepared baking sheet to ensure even roasting.
Roast in the oven for 20 minutes until the chicken is cooked through and the vegetables are tender.
Remove the pan from the oven, pour the tomato puree over the mixture, and stir gently to combine.
Return the pan to the oven for an additional 5 minutes to allow the sauce to thicken and flavors to meld.
Finish the dish by sprinkling fresh lemon zest over the top before serving warm.