T.C.
When I was two, all I wanted to eat was green beans. Mama was worried and called her mother-in-law. I loved Grandma's response. "As long as she is eating, let her be. It is not junk food, her body just must be needing something in the beans." It only lasted a couple of days and I moved on to other fruits and vegetables.
My son is also a rather picky eater. For several days to a week he will only want one or two food items. This week it is bacon sandwiches. What I usually do is tell him that he can have one at either breakfast or lunch, but the other two meals, he needs to try what we are eating. If he tries it, and doesn't like it - then I will make him what he wants. But, he must try the new food first. Usually, he ends up enjoying it and eating the meal with the family.