Step 1

Preheat oven to 200°C/180°C fan-forced. Lightly grease roasting pan. Place lamb in pan. Combine oil, rosemary and garlic in a bowl. Rub half the oil mixture over lamb. Season with salt and pepper. Roast for 15 minutes.

Step 2

Reduce oven temperature to 180°C/160°C fan-forced. Roast lamb, basting with remaining oil mixture every 20 minutes, for 1 hour 15 minutes for medium or until cooked to your liking. Add potatoes to pan for last 40 minutes, turning halfway through cooking.

Step 3

Remove lamb from oven. Cover loosely with foil. Stand for 10 minutes. Carve. Serve with potatoes.

Step 4

Basic Gravy: Transfer meat (and any vegetables) to a plate to rest. Combine stock and wine in a jug. Skim fat from roasting pan, leaving 1 1/2 tablespoons pan juices and fat in pan. Place pan over high heat. Add flour. Cook, stirring with a wooden spoon, for 1 to 2 minutes or until mixture bubbles and becomes golden. Add juices from resting meat. Slowly add stock mixture to pan, stirring constantly. Cook, scraping pan, for 8 to 10 minutes or until thickened.