Boil milk, remove from heat. Beat egg yolk with sugar until thick and pale. Beat in flour and cornstarch. Pour hot milk into yolk mixture and whisk. Return to sauce pan cook over medium heat, whisk constantly, until mixture boils (it will be lumpy). Whisk until smooth. Continue to cook gently for 2 minutes, whisking constantly. Remove from heat and pour into a bowl. Stir in vanilla and rub a piece of cold butter over the surface of cream to prevent a skin from forming.

Mix water and sugar in pan. Add cornstarch and crushed strawberries and mix well. Boil for 2 minutes until clear and thick. Cool.

Take the center out of cooked pastry puff. Fill with 2/3 cream filling. Top with strawberry glaze. Garnish with fresh strawberry and fresh mint leaf, dust with powdered sugar.