Gradually add in cold water, stirring each time until you can press it together. Form it into a disk, wrap in plastic wrap and refrigerate for at least 2 hours, or freeze for 30 minutes until chilled.
Roll out pie crust dough to fit a 9" pie plate.
Cook over medium to medium-high high, whisking constantly, until thickened. It will be thick, slightly thicker than pudding, when warm. This can take 10-15 minutes, but don't rush it. Once thickened, remove from heat and stir in butter.
Pour hot filling into the pie crust, set aside and make the meringue.
(Nutrition information provided is an estimate and will vary based on cooking methods and brands of ingredients used.)