Cook the pasta according to the instructions on the packet.
Meanwhile, cut the spring onions into rings, quarter the tomatoes and cut the mozzarella into small pieces. Cut the chicken into bite-sized pieces and fry in the pan.
Add the spring onions and fry briefly. Drain the pasta and add to the pan. Then stir in the tomatoes and then the mozzarella.
When the cheese has melted, remove the pan from the heat and serve the pasta immediately.