For the garlic butter: Mix together ingredients in a small bowl until smooth.
Cut a slit along the side of each chicken breast to make a pocket. Spoon garlic butter into pockets. Wrap each chicken breast in puff pastry. Cook on an oiled tray in the oven for 40 mins or until the pastry is puffed and golden.
Meanwhile, prepare the creamy garlic sauce: Melt the butter in a small saucepan over medium heat; add the garlic, cook for 1 minute. Stir in the flour and cook for 1 minute or until mixture bubbles. Gradually whisk in the milk; stir over medium heat until sauce bubbles and thickens. Stir in te parsley.
Serve the chicken parcels with the creamy garlic sauce.