Appearance doesn't mean it is safe to eat. People don't tend to eat food that looks undercooked - they get ill eating food that looks okay but actually isn't.
Ground meat, from a food safety point of view, is considered a high risk food. The fact that it is actually makes the appearance of the outside of the food and even less reliable indicator of safety. There are two age groups that are more susceptable to food poisoning and suffer more as a result of it: the very young and elderly people. The Op is serving "high risk" foods at a school fair. I think the fact that he is trying to take food hygiene seriously is to be applauded.
Ground meat, from a food safety point of view, is considered a high risk food. The fact that it is actually makes the appearance of the outside of the food and even less reliable indicator of safety. There are two age groups that are more susceptable to food poisoning and suffer more as a result of it: the very young and elderly people. The Op is serving "high risk" foods at a school fair. I think the fact that he is trying to take food hygiene seriously is to be applauded.