how can I teach my 5 year old son to eat vegetables.

It helps kung nakikita nya na nag ggrow ang vegies himself (the reason why Child Development Centers have Gulayan sa Paaralan or backyard garden) hanggang eventually ma-serve sa hapag kainan niyo. You have to show you are enjoying vegetables and fruits too, as it is. Serve them as is. Honestlt, kids appreciation of vegetables and fruits starts in the womb kasi they gwt to recognize the taste after sila ipanganak, according to studies.