Preparation / Directions:
Cream the butter with lard. Add egg and sugar. Beat well. Add flour, 1 cup at a time. The dough will be mealy. Work quickly with your hands to gather dough into a ball. Knead lightly so the mixture adheres. You may chill it at this point while making the filling.
Egg Custard Filling: Be sure all the ingredients are at room temperature. Beat whole eggs at low speed with egg yolks well. Do not over beat, add sugar, then milk, then half and half. Let mixture rest 10 - 15 minutes. Skim foam from mixture.
Separate dough into 24 ball. Press each into 2 1/2 inch tart shell to~ an even layer across the bottom and all the way up the side. Fill shell with filling almost to the top. Preheat oven to 300. Place tarts on cookie sheet and bake for 45 minutes. Cool for 10 - 15 minutes. Loosen slightly by inserting a toothpick along the sides. Tart shell should unmold easily.
Rhoda Yee's comments: It is important that the ingredients for the filling be at room temperature and beaten over a bowl of warm water. Cold ingredients will cause filling to separate during baking. By skimming off the foam, the custard will have a golden, creamy appearance with a velvety smooth texture which is a most unique and delightful gastronomic treat! Do not bake at high heat, this will cause the custard to bubble up like a balloon and burst.
From "Dim Sum" by Rhoda Yee