I love this and have made it for several dinner parties. Just be sure that you don't overcook the asparagus. After the 3 min. of cooking, I drop it into ice water to stop further cooking. Can do this a day ahead and then reheat the asparagus in the mustard "sauce" at the last minute before serving. Asparagus need not be piping hot to be eaten.
I hate to be the lone dissenter, but I thought this was a just a good, not outstanding recipe. It is easy to prepare, and quick. However, it just tasted like mustard on asparagus. Not particularly nuanced or special, in my opinion. I much prefer another Cooking Light asparagus recipe; I think it is called Asparagus with Balsamic Browned Butter.
This recipe is simple and delicious! I made it the first time for company and have made it several times since. It's a great side dish - I usually double the sauce when I make it! Highly recommended.