Basic Custard Sauce
A basic sauce to serve warm over bread puddings, steamed puddings or sponge cakes. 

4 egg yolks
1/2 cup sugar
1 tablespoon flour
1 cups whole milk
1 teaspoon vanilla

Place water in bottom half of double boiler and allow to preheat.. 

In a small bowl, mix flour into sugar.  In the top of a double boiler, whisk egg yolks until creaming. Then whisk in sugar and flour and whisk. Place over boiling water and adjust heat so that water simmers.  Cook until thicken.  Add vanilla and serve.