01 - Preheat oven to 400°F (200°C) and line a large sheet pan with parchment paper.
02 - Arrange chopped red bell pepper, zucchini, red onion, and chicken thighs onto the prepared sheet pan.
03 - In a small mixing bowl, whisk together olive oil, balsamic vinegar, dried Italian herbs, salt, and black pepper.
04 - Drizzle marinade over the chicken and vegetables. Toss thoroughly using tongs or a spoon to ensure even coating.
05 - Roast in the oven for 25 to 30 minutes, flipping chicken and vegetables halfway through, until chicken is cooked through and vegetables are tender.