To thaw or not to thaw?

[Longingforatikihut]

I have a roast from frozen gammon joint in the freezer. (Bought for a guest that never showed).

With energy increases I'm contemplating defrosting it before cooking to cut down on how long the oven is on. Is this dodgy AF? Am I going to give myself some dire poisoning?

(Embarrassingly I used to work in food microbiology. Its left me a little fearful of not always following the instructions on the packet)

Does it say not to thaw or does it just say ‘best cooked from frozen’? No reason why you can’t thaw it but I’d not really know how long to cook it for if I didn’t follow the instructions tbh, a raw gammon joint always has the cook for x time per kg on it but a cook from frozen won’t have.

I'm wary of "cook from frozen" instructions as I've had problems.
Depends so much on whether your oven temp is accurate, etc.
I usually defrost slowly, & adjust time accordingly.
BBC has a "roast timer" that will give cooking times for a joint.

I wouldn’t be concerned with defrosting it. I’d defrost in the fridge leaving 10-12 hours per kg of meat.