Snap off tough ends of asparagus. Bring 4 quarts water to a boil in an 8-quart stockpot. Add half of asparagus; cook 3 minutes. Remove asparagus from stockpot. Rinse with cold water; drain and pat dry. Repeat procedure with remaining asparagus.
Combine the Dijon mustard, lemon juice, and salt in a small bowl. Place a large nonstick skillet over medium heat until hot. Add mustard seeds; cook 1 minute, stirring constantly. Add asparagus and mustard mixture, and cook 2 minutes or until thoroughly heated.
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.