Take 2 ziptop bags and add 1 half of the chicken to each.
Divide the marinade evenly between them.
Squeeze out as much air as you can and seal the bags.
Massage the marinade into the chicken.
Refrigerate for at least an hour (overnight is best).
Preheat oven to 400°F/200°C..
Spray a large baking sheet with non-stick spray.
To a large bowl add the cumin, coriander, salt pepper and olive oil. Add the vegetables and toss so they are evenly coated. Arrange the vegetables in an even layer on the baking sheet.
Remove the chicken halves from the bags and pat dry.
Rub the skin side of the chicken with olive oil. Sprinkle with 1 teaspoon cumin, ¼ teaspoon salt, and a little pepper.
Lay the chicken halves over the vegetables and garnish with lemon slices.
Roast for 40 to 50 minutes until the juices from the chicken run clear and a meat thermometer reads 165 degrees F when inserted into the thickest part of the leg.