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 place them in a large mixing bowl.
Dice the eggplant, zucchini, red bell pepper, and yellow onion into uniform 1-inch pieces and add them to the bowl with the chicken.
Mince the garlic cloves and add them to the mixture along with the olive oil, herbes de Provence, sea salt, and black pepper.
Toss everything thoroughly until the chicken and vegetables are evenly coated in the oil and seasonings.
Spread the mixture in a single layer on the prepared baking sheet, ensuring there is space between the pieces for even roasting.
Roast 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, warm the tomato puree in a small saucepan over low heat.
Once the roasting is complete, transfer the chicken and vegetables to a serving bowl and gently fold in the warm tomato puree before serving.