Is it a condition of his employment; that would make life easier.

Food law does not require everyone to be trained via an official course such as the CIEH NVQ level 2 or equialent online training which is recommended for caterers. Training should be appropriate to the activity and level of supervision. If there is someone trained in the premise and able to supervise them then that would be adequate if they were not carrying out any high risk activity. Hygiene awareness would be the minimum required which your friend could carry out (and record what has been done) assuming she has at least NVQ Level 2 and preferably Level 3 (if they are supervising their staff). Personally if I was your friend I would not keep employing someone who refused to do any training. How do they know that they are bothering to obey basic hygiene rules. As an ex inspector I would have served a formal letter requiring training or a hygiene improvement notice if the employee had any supervisory duties or was carrying out any high risk activities. It is the food business operator who has responsibility to ensure their staff are adequately trained.

Listen to Ron as there may be an underline personal problem Additionally you do not get adequate feed back in my view from on line courses as usually its a cheap tick box exercise