Preheat your oven to 400°F and line a large baking sheet with parchment paper.
Dice the eggplant, zucchini, and red bell pepper into 1-inch cubes.
Place the vegetables on the baking sheet, drizzle with 0.5 tablespoons of olive oil, and season with the sea salt and black pepper.
Roast the vegetables for 20-25 minutes, tossing halfway through, until they are tender and slightly caramelized.
While the vegetables roast, dice the chicken breast into bite-sized pieces.
In a large skillet, heat the remaining 0.5 tablespoons of olive oil over medium heat.
Add the diced onion and minced garlic, sautéing for 3-4 minutes until translucent and fragrant.
Add the chicken to the skillet and cook for 5-7 minutes until browned and cooked through.
Pour in the crushed tomatoes, dried oregano, and dried thyme, then simmer the sauce on low for 5 minutes.
Gently fold the roasted vegetables into the skillet with the chicken and sauce to combine.
Serve the ratatouille warm, garnished with the freshly chopped basil.