[header] How to cook roast lamb [title] Preheat the oven to 400 ° f (204 ° c). [step] It takes only a few minutes to prepare the roast for cooking, so preheat the oven before you get started. [title] Place the leg of lamb in a roasting pan. 
[step] Choose a metal, glass or ceramic pan that's just large enough to hold the entire leg of lamb. If you're roasting the lamb with vegetables, it's fine to use a slightly larger roasting pan.