Preheat oven to 200⁰C and line a large oven tray with baking paper. Place racks on oven tray and brush evenly 2 tablespoons of oil over each rack; season to taste. Roast for 25 minutes for medium or until cooked to your liking; rest for 15 minutes covered loosely with foil before serving.
Meanwhile, boil potatoes in saucepan of boiling salted water for 30 minutes or until cooked. Drain and transfer to a large heatproof bowl. Using a potato masher or ricer, mash potatoes with milk and remaining 2 tablespoons olive oil. Season to taste.
Preheat a lightly greased large char-grill pan or barbecue to high. Place zucchini, capsicum, eggplant, herbs, garlic and oil in a large bowl; season to taste and toss well to combine. Cook capsicum for 5 minutes turning frequently or until charred and cooked. Cook eggplant for 3½ minutes each side until charred and cooked. Cook Zucchini 2 minutes each side until charred and cooked.
Divide mash, char-grilled vegetables and Lamb Racks among plates. Serve with charred lemon wedges.
Substitute Lamb rack with forequarter rack or loin chop. Other alternative to lamb racks are loin roasts, mini roasts and neck fillet roasts.
Ask your butcher to French-trim your rack for you. To French trim your rack is to scrape away any of the fat that clings to them.
For best cooking remove rack from fridge for 30 minutes before cooking, to bring to room temperature.
Use a meat thermometer to tell when you lamb is done.