Roast lamb .... is this a long enough cooking time?

[nappyaddict]

I have half a leg of lamb which I froze from fresh.

I have looked it up on the internet which says I should cook it for 30 mins at 220 C and then 20 mins per kg at 160 C. If it is frozen it says I should cook it for 1.5 times longer. My lamb is 1.426kg so that work out at cooking it for 45 mins at 220 C and then about 45 mins at 160 C. This doesn't seem very long but I do like my meat rare.

I personally, wouldnt cook it from frozen. Can you defrost it first?

I wouldn't either, I'm never sure about frozen meat being nice cooked from frozen, so always defrost.
I actually have lamb shoulder for tomorrow, which I'll defrost overnight.

lamb is ok cooked from frozen as is beef. i would say that will be prety pink though, its quite small so should be ok and you will know if you need to do it any longer.

I wouldn't. I'd defrost and eat tomorrow instead.