Can an employer MAKE you use your right hand when youre left handed?

Generally left hand is used to clean as* after shi**ing. So, its not nice to use to serve with left hand or eat with left hand.

That is the most retarded crock of poo I have ever heard. So retarded in fact that I'm almost tempted to call BS on the question itself.

Yes they can make you do this. There is no special protection for left handed people.

I would use my left hand, eff that noise. And when dumb@$$ mentions it again, I would ask calmly and politely, if she would like to take the discussion up with my lawyer and continue on with my work. Either that, or I would - drop every single thing I put my hand on. Everything. Then she would try to charge you. Then you say: well it's an act of god and you can't charge me - the labor board says so. I would truly play some games with this one. Oh yes.

It could be seen as a form of discrimination, though I'm not sure if it'd be on par with things like age/race/gender discrimination. All in all it's a pretty silly rule that doesn't seem like it could be enforced unless using your right hand is proven to be more beneficial for the type of work that you do.

They are racist. Report them to the police for abusive behaviour.

There is no rule. Your employer is an idiot. However, do not tell him that. Ignore him but, with a smile. If he mentions it again, ask him if he would rather have a customer served perfectly well with a left hand or whether he would rather risk the food dumped in the customer's lap. If that doesn't shut him up, try this: "Left or right handedness is not the mark of a good job or a bad job". If that doesn't shut him up, then just tell him you are trying but when you have trouble, you switch back to get the job done properly and efficiently. Then, ask him "you don't want me to be slow, do you?". These phrases are not sarcastic, rude or argumentative, just to the point. Maybe he will get the point, at some point.