The characteristics of a really good...mac and cheese are that it should have a gooey, unctuous, cheesy inside, topped by a crispy, intensely cheesy crust. This version fulfills those requirements. Serve with a plain green salad. You will not need anything else, unless it's a good red wine. Be prepared to compensate with spare eating for days afterwards. To my mind, this is the perfect thing to serve at a casual dinner party with close friends.
With a rich dish like this one, you often eat less than you otherwise would, making it a thriftier choice than you might think. Oh, what a lame excuse. After reading her description, I'm ready to throw thrift (and calories) to the wind one night just to have some of this.