Place chicken, water, wine and bouillon cubes in a medium pan. Bring to a boil, lower heat and cook gently, uncovered for 15 minutes. Remove from heat and allow to cool. Set aside one cup of broth and chop chicken into chunks.
Preheat oven to 400ºF (200ºC). Coat a deep 8-inch (20cm) pie dish with cooking spray. Microwave carrots and peas for 2 minutes. Drain. Heat oil in a medium nonstick pan, add onions and cook until soft. Stir in flour and cook over low heat for 2 minutes. Remove pan from heat and stir in milk and reserved broth. Return to heat and cook, stirring, until mixture boils and thickens. Add carrots, peas, chicken and corn.
Pour chicken into prepared dish. Layer sheets of phyllo over pie, trim edges and press down firmly to seal. Lightly coat with cooking spray.
Bake for 10 minutes, lower temperature to 350ºF (180ºC) and bake until golden brown, about 20 minutes more.