In a small bowl, whisk together the olive oil, lemon juice, lemon zest, oregano, thyme, garlic, salt, and pepper.
Place the chicken breasts on a large sheet pan, and pour half of the lemon herb mixture over the chicken, ensuring it's evenly coated.
In a large mixing bowl, combine the broccoli, carrots, bell peppers, and red onion. Drizzle the remaining lemon herb mixture over the vegetables and toss to coat.
Spread the seasoned vegetables around the chicken on the sheet pan.
Bake in the preheated oven for 25-30 minutes, or until the chicken is cooked through and the vegetables are tender.
Remove from the oven and let it rest for a few minutes before serving.
Garnish with fresh parsley before serving.
Notes
You can substitute the vegetables with your favorites or whatever you have on hand.