Lower the oven to 190C/170C fan/gas 5 and cook for another 15-20 mins per 500g (1 hr – 1 hr 20 mins for 2kg leg) depending on how pink you like your lamb.
Place the fillet in the oven and reduce the temperature to 425°F. Roast for about 25 minutes for rare or until a meat thermometer reads 130°F when inserted.
If you're cooking in the oven, brown the meat and onions, and bring to a simmer first on the stovetop. Then put in the oven, start the temp at 350°F for 15.
Embedded ticks usually are oval shaped, firm, dark red or brown, and have no hairs growing out of them, while moles and skin tags tend to be irregular, soft.