Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
Dice the eggplant, zucchini, and red bell pepper into uniform half-inch cubes.
Toss the diced vegetables on the baking sheet with half of the olive oil and the herbes de Provence.
Roast the vegetables for 20 minutes until they are tender and slightly caramelized around the edges.
While the vegetables roast, heat the remaining olive oil in a large skillet over medium heat.
Add the ground chicken breast and diced yellow onion to the skillet, cooking until the chicken is browned and the onion is translucent.
Stir in the minced garlic and cook for 1 minute until aromatic.
Pour in the tomato puree and lower the heat to a simmer, allowing the flavors to meld for about 5 minutes.
Gently fold the roasted vegetables into the chicken and tomato mixture.
Season the ratatouille with sea salt and black pepper.
Garnish with freshly torn basil leaves before serving warm.