Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Dice the chicken breast, eggplant, zucchini, red bell pepper, and red onion into uniform 1-inch pieces.
In a large bowl, toss the chicken and vegetables with olive oil, sea salt, and black pepper until evenly coated.
Spread the mixture in a single layer on the prepared baking sheet and roast for 20-25 minutes until the chicken is cooked through and vegetables are caramelized.
While the vegetables roast, place the tomato puree, minced garlic, and dried oregano in a small saucepan over medium heat.
Simmer the sauce for 5-7 minutes to allow the flavors to meld, then remove from heat.
Once the roasting is complete, transfer the chicken and vegetables to a bowl and gently fold in the warm tomato sauce.
Garnish with fresh lemon zest and chopped basil before serving.