2 year old taking forever to chew food.

Just wanted to ask other mums what they do when their child takes forever to chew their foods?
I have a 2 year old and sometimes he takes a good 10 mins to chew one mouthful of food. For example he had mac and cheese for lunch and took ages to chew each mouthful. Where as things like chicken nuggets or toasted sandwiches he eats easily. So its not a matter of the food being too hard for him to chew. He has a mouthful of teeth, only missing a few. It is so frustrating when im helping him to feed himself and have other things to do and he decides to take forever to chew his lunch. What have other mums done??