Preheat oven to 200°C/392°F
1. Place the chicken breasts in a saucepan, skin side up. Add 1 ½ cups water, bayleaf and sliced onion. Cover and poach gently over a medium heat for 10 minutes or until the chicken is just cooked through. Turn the chicken over halfway through cooking. Remove the chicken from the pan, strain the cooking stock and reserve 1 cup. Remove the skin from the chicken, cut the breasts into bite sized pieces and set aside.
2. Heat the butter in the saucepan. Add the sliced leek and crushed garlic and cook until the leeks starts to soften, but not brown. Stir in the flour and cook for 1 minute. Gradually add the reserved stock and milk, stirring constantly until sauce boils and thickens. Continue cooking a further 2 minutes. Remove from heat.
3. Stir the cooked chicken and the Wattie’s Frozen Chunky Mix into the sauce. Spoon into a lasagne style dish.
4. For mashed potato topping, cook the Wattie’s Frozen Steam ‘n’ Mash according to packet directions. Place in a bowl and mash adding milk and butter until smooth and creamy. Spoon over the chicken and rough the top with a fork. Sprinkle over grated cheese. Bake for 15-20 minutes, until hot and golden.