S.S.
I make my son try it, I never make him finish a full portion. I always serve something that I know he'll eat - that is healthy. He gets a small portion of known food and half a bite of new food. When his plate is empty, he may have more of the food of his choice, or he may have a snack at least an hour later. If it is not empty, the only snack available until his plate is empty is what is on his plate (again - we wait an hour between meal and snack). Please note that I only put about 1/3 of what I think he will eat on that plate - I never force my kids to eat - my parents gave me a gorgeous weight problem with the clean your plate club.
S.