Make sure that you check your school's policies on this. I taught a health class and had to get permission to do lessons with food when discussing nutrition - you may have to bring them in at or after lunch depending on your site/district. I will say the lesson was a huge success, and the students started bringing in new recipe ideas they had tried or wanted to try. Also be aware of allergies - some unusual ones do crop up (kiwi, banana, onion...), adaptions can be made. Have fun