i"m so glad i continiued to scroll down to Gamma G's post because the rest that I read just about made my blood pressure boil.
Ok First The teacher called you and asked for advice-- little clue here, this isn't her first trip around the block, She Did that to NICELY and UNDENSIVELY inform you that there was a problem and that she was willing to work with you.
I highly doubt you or any of the responders would have liked it very much if she had told you in no uncertain terms what a stubborn defiant rule breaking little punk your kid was being. ( which he wasn't he was being a stubborn 3 yo new to the school enviroment)
So I think you owe that teacher a Big THANKYOU and you had better appreciate how kind she was being. ( not that you don't Mommy18 --but some of these other ladies on here were way way off imo)
Your suggestion was great, Take it a step further and go over the routine with him at home. Start making him wash his hands before dinner if you don't already. Instill in him that he has to listen to the teacher, she is there to help him and keep him and the class safe- just like a police man keeps us safe, the teacher keeps you safe by helping you to wash your hands so germs don't get in you and make you all sick and yucky. tell him how proud you are when he follows the rules.
I'm going to be honest with you and i'm not trying to kick you when you are down. Honestly, if you feel bad about what is happening I would take that as a sign that you are a good mom and you do want your kid to behave. The tone of your post though, made me feel like he is a difficult kid at home too and that have these same issues with him at home. The difference is there are probably at least 10 other kids in his class that have to suffer or at least wait for her to deal with him when these situations come up. It's bad enough one on one but when you have other kids involved its triple yucky. If i'm wrong then i'm sorry but the best thing you can do is be very firm and consisten with his behavior at home so he wouldn't even think to get away with this stuff at school or in public. That doesn't mean smacking him, it just means you don't say 10 times don't do that or you have to go to your room and then never ever make him go to his room.
Help her out, let her know what he loves so she can use that as incentive, If he loves dinosaurs maybe she can offer to let him use a special dino toy after he has his meal.
This could be an isolated incident and maybe he was tired from the night before or maybe he is sick. But if he is consistently a very difficult child you might want to see if the teacher thinks he needs to be evaluated, I did see quite a few people on here say their kids had undiagnosed ADD or Autism and where just considered bad, and getting approprite help can make the world of difference.
But it might be totally normal too, Make sure he gets lots of rest, and healthy food, and knows the rules and knows the consequences.