Preheat the oven to 200°C. Combine the honey, lemon juice, soy sauce and garlic in a medium bowl; put aside.
Lightly spray a small baking dish with cooking spray. Add the zucchini, parsnips, carrots, celery and capsicum and roast for about 20 minutes or until the vegetables are lightly browned.
Top the vegetables with the rosemary and pour over the stock. Arrange the lamb racks on top of the vegetables, baste with the honey sauce, and roast for 20 minutes for rare (lamb will be pink), 30 minutes for medium, or 40 minutes for well done. Continue basting with the sauce occasionally.
Remove the baking dish from the oven and put the lamb racks and vegetables aside; cover and rest for 10 minutes before carving the meat.
Boil the pan juices until they thicken slightly. Serve the sauce with the lamb and the vegetables.