Place chicken in a saucepan with enough water to cover and bring to the boil. Cook for 20 minutes or until no longer pink and juices run clear. Remove from saucepan and shred.
Preheat oven to 180 C / Gas 4. Dissolve the stock cube in hot water. In a large bowl, mix the chicken with the stock, cream cheese and 1/2 of the mozzarella cheese.
Spread 1/3 of pasta sauce in the bottom of a 20x30cm baking dish. Cover with the chicken mixture and top with 3 lasagne sheets; repeat. Top with remaining sauce and sprinkle with remaining mozzarella cheese.