This is a very tart, lemony and sweet curd. The directions given in the Magnolia Bakery Cookbook which I recently bought, gives very shallow directions with just enough information to make the recipe. It was my first time making custard/curd and it was surprisingly good. I hope you like it. Note: it is called a filling because it can be used as a cake filling but it is also wonderful on toast or scones for a sweet breakfast or teatime treat. This recipe yields 3 1/2 cups or enough filling for 1 two or three layer 9-inch cake.