Other choices around food, might be: Do you want 3 green beans or 4 green beans? Do you want a hard boiled egg or a very hard boiled egg? You child will learn that he or she has some control in life, but these are not life threatening, or illegal! Sometimes, it might be necessary to give in, if the choice really doesn't work out, but sometimes, you just have to stick to the decision that was made.
These are small decisions, which lets a child realize that making a choice results in some control, yet has a consequence. Learning that we all make poor decisions in life is a life truth. Practise making decisions where the consequences are fairly easy to live with, and your child will gain confidence in his or her own decision making skills.