This really is a great, and simple recipe. The sauce is pretty rich, so you want something just thick enough to coat the meat, but not so thick that it covers it up. Having said that, if you cook it a little further, until it almost starts to simmer, it will get a bit thicker, if that's your preference. Just don't go too far, or the yolks may start to form curds, and you'll lose the silkiness. Serve over buttered toast or in freshly baked puff pastry shells.
You can substitute brandy for sherry, if desired.
Get the recipe for Puff Pastry Shells.