My son is now 2 years old, but I had the same problem with him when he was younger. I wanted to make him change from rice cereal to porridge (粥). He even threw up the porridge. That was a real vomiting!!! He swallowed 2 spoons and then vomited everything out from the stomach!!!
So, I tried to mix a few spoons of porridge with the rice cereal that he had been having and liked. I then gradually increased the amount of porridge and reduced the amount of rice cereal. He was doing really fine and eventually liked taking porridge alone with some meat and vegetables.