In a small bowl, combine the olive oil, lemon juice, lemon zest, minced garlic, dried oregano, dried thyme, salt, and black pepper. Whisk together until well mixed.
Place the chicken breasts in a shallow dish or resealable bag, pour the marinade over them, and ensure they’re evenly coated. Let them marinate for at least 10 minutes.
While the chicken marinates, chop the cherry tomatoes in halves, dice the bell pepper, slice the zucchini, and chop the red onion. Toss these veggies lightly in a drizzle of olive oil, and season with a pinch of salt and pepper.
Heat your large oven-safe skillet over medium-high heat. Add a tablespoon of olive oil to the pan. Remove chicken breasts from marinade (reserve the marinade) and sear them for 3–4 minutes per side until golden.
Push the chicken to the edges of the pan and add the prepared vegetables to the center. Pour the reserved marinade over everything.
Transfer the skillet to a preheated oven at 400°F (200°C). Roast for 15–20 minutes or until the chicken reaches 165°F (74°C) and vegetables are tender.
Remove the pan from the oven and sprinkle freshly chopped parsley over the dish. Serve immediately, spooning the pan juices over the chicken and veggies.