Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Cut the chicken breast into 1-inch cubes and dice the eggplant, zucchini, and red bell pepper into similar bite-sized pieces.
In a large mixing bowl, combine the chicken and vegetables with olive oil, minced garlic, dried oregano, sea salt, and black pepper.
Toss everything thoroughly until evenly coated, then spread the mixture in a single layer onto the prepared baking sheet.
Roast for 20 to 25 minutes, or until the chicken is cooked through and the vegetables have developed golden, caramelized edges.
While the vegetables roast, gently warm the tomato puree in a small saucepan over low heat.
Remove the sheet pan from the oven, transfer the roasted chicken and vegetables into a serving bowl, and fold in the warm tomato puree.
Garnish with freshly chopped basil and lemon zest for a bright finish before serving.