Bring a large pot of lightly salted water to a boil. Cook the lasagne sheets for 8 to 10 minutes, or until al dente. Drain, rinse with cold water and set aside.
Meanwhile, place the chicken in a saucepan with just enough water to cover and bring to a boil. Cook for 20 minutes, or until no longer pink and juices run clear. Remove from saucepan and shred.
Preheat oven to 180 degrees C. Dissolve the stock cube in the hot water. In a large bowl, mix the chicken with the stock cube, cream cheese and 1 cup mozzarella cheese.
Spread 1/3 of pasta sauce in the bottom of a 20x30cm baking dish. Cover with the chicken mixture, top with 3 sheets lasagne and repeat. Top with remaining sauce and sprinkle with remaining mozzarella cheese.