Hi, can you ask his parents? What are his food choices at home. Some children have food texture sensitivity. I have exprienced the very same kind of behavior in my group and or new children joining to daycare. I usually start very slow. First serving the very same thing that everyone is eating but in a smaller amount. I usually ask them to try just two bites and then they can have what they like ex. Their favorite yogurt. I ask them if they want to be helped by cutting their food in small pieces they usually like that. But I've also a small food processor so I pureed things and mixed in their yogurt. At first not too much and I have slowly increased the amounts until they develope a taste for that food.

I always remember in a nutrition course I took "it takes 40 times ta sting a new food before our palate becomes familiar to it"; and works even for adults. Sometimes we make the mistake of not serving a certain kind of food because the child doesn't like it, leaving that poor child with a limited poor food choice. Just keep trying at times peer pressure works wonders.