My mother fell in love with a dessert we had in a restaurant, and I'd like to replicate it for her birthday. It was a rectangular sheet of puff pastry on the bottom, with glazed assorted fruit slices on top. It's the custard in between the fruit and pastry that I don't know how to make. I don't have much custard experience. Can anyone help me make a custard that would go with these other elements of the dessert?