How to Make It
Wash brussels sprouts thoroughly, and remove discolored leaves. Using a sharp knife, cut off stem ends, and cut a shallow X in bottom of each sprout. Bring water to a boil in a medium saucepan; add brussels sprouts. Cover, reduce heat, and simmer 12 minutes or until brussels sprouts are tender. Drain and keep warm.
Melt margarine in a small heavy saucepan over low heat; add flour, stirring until smooth. Cook, stirring constantly, 1 minute. Gradually add milk; cook over medium heat, stirring constantly, until mixture is thickened and bubbly. Add cheese and mustard, stirring until cheese melts. Spoon sauce over warm brussels sprouts.
Cooking Light Light Cooking for Two