1/4 to 1/3 cup orange flavored liqueur (recommended: Grand Marnier)
In a saucepan on medium heat, heat the milk and half-and-half to just below the simmering point. Remove the pan from the heat and add the white chocolate. When the chocolate is melted, add the vanilla, vanilla bean seeds, and 1/4 to 1/3 cup orange liqueur, according to taste, and whisk vigorously. Reheat very gently and serve.