To get started, in a large measuring cup or small bowl, whisk together the 6 tablespoons olive oil, juice and zest of two lemons, 2 tablespoons dried oregano, 2 teaspoons onion powder, 2 teaspoons garlic powder, ½ teaspoon kosher salt, and ½ teaspoon black pepper.
Cut the 2 boneless skinless chicken breasts into small bite-sized pieces. The key to cooking the chicken and vegetables quickly and evenly is to make sure everything is cut to the same size.
Pour half the marinade into a zip-top bag and add the chicken pieces. Seal the bag, removing as much air as possible. Gently squish and turn the bag so that the chicken is evenly coated with the marinade, then lay the bag flat in a baking dish to catch any drips.
Place the chicken in the refrigerator to marinate for at least 30 minutes or up to 8 hours. The longer the chicken marinates the more intense the flavor will be. Refrigerate the remaining marinade in a separate container.
Remove the chicken from the refrigerator so that it comes to room temperature and preheat the oven to 425 degrees F.
Cut the 2 medium zucchini into ¾ inch dice (you can leave the peels on). Leave the 10 oz cherry tomatoes whole. Place the vegetables in a bowl and toss them with the remaining marinade.
Line a sheet pan with foil or parchment paper. Arrange the vegetables and the chicken in a single layer on a rimmed baking sheet. Bake for 15 minutes.
Remove the chicken and vegetables from the oven and top them with ½ cup mozzarella cheese and ¼ cup parmesan cheese.
Return the sheet pan to the oven and bake for an additional 10 minutes or until the chicken is cooked through and the cheese has melted and browned slightly.
Chicken is done when the internal temperature reaches 165F. The cooking time will vary based on the size of your chicken.