Preheat the oven to 425°F. In a large bowl, whisk together the oil, lemon juice, garlic, oregano, thyme, Dijon mustard, tomato paste, salt, and pepper. Reserve ⅓ of the marinate.
Place the chicken thighs in a bowl and then use your hands to toss the chicken in the marinade and make sure it’s well coated. Marinate the chicken for 10 to 15 minutes while you prep the veggies.
While the chicken is marinating, add bell pepper, red onion, and potatoes onto the baking pan and drizzle the remaining marinade on top. Toss together to coat the vegetables.
Add the chicken thighs on top of the veggies, sprinkle with ¼ cup of parmesan cheese and bake for 30 minutes.
Remove the pan from the oven, add zucchini, mix it a little bit to coat with the juice from the pan and then place it back in the oven for another 10 to 15 minutes, or until the vegetables are softened and the chicken is cooked through to 165°F.
Broil for 1-2 minutes at the end if you would like to get the chicken skin even crispier. Be careful to not burn parmesan and the chicken skin during this step.
Sprinkle the chicken and vegetables with chopped fresh parsley and remaining parmesan cheese before serving. Enjoy!