Preheat the Oven: Begin by preheating your oven to 400°F (200°C). A hot oven ensures perfectly roasted chicken and veggies.
Prepare the Chicken Marinade: In a small bowl, combine olive oil, lemon juice, oregano, basil, garlic powder, salt, and pepper. Mix it well and set it aside.
Marinate the Chicken: Place the chicken breasts in a large bowl or plastic bag. Pour the marinade over the chicken, making sure each piece is evenly coated. Let it sit for at least 15 minutes (or up to 2 hours in the fridge for deeper flavor).
Arrange the Vegetables: In a large baking dish, spread out the sliced bell peppers, zucchini, and cherry tomatoes. Sprinkle salt and pepper over the veggies for added taste.
Add the Chicken: Lay the marinated chicken breasts on top of the vegetable bed. Scatter the Kalamata olives across the dish.
Bake: Cover the baking dish with aluminum foil and pop it into the oven. Bake for 25 minutes, then remove the foil and bake for an additional 10-15 minutes, or until the chicken reaches an internal temperature of 165°F (75°C) and the veggies are tender.
Finishing Touch: Once done, take it out of the oven and sprinkle feta cheese and fresh parsley on top if desired. Serve hot and enjoy the Mediterranean flavors!