Preheat oven to 190°C. Wash the Sadia Whole Chickens thoroughly, inside and out, in salted water and dry with a paper kitchen towel.
In a bowl, mix together the crushed garlic, cumin, coriander, cinnamon, lemon juice, sea salt and pepper and olive oil.
Place the 2 halved lemons into each cavity. Tie the legs together with a kitchen string and fold under the wing tips. Place the chickens in a large roasting dish and cover with the spice and oil mixture. Pour the water into the bottom of the roasting pan and cover loosely with baking paper.
Bake for 1 hour and then remove from the oven and add the grapes. Drizzle the chicken with honey and the grapes with balsamic vinegar. Return to the oven for 20-30 minutes or until the juices run clear when a skewer is inserted into the thickest part of the thigh.
Transfer the chickens and grapes onto a serving platter. Skim the fat off the pan juices and boil to reduce and thicken.
Serve the chicken with the juices on the side.