Finely shred enough peel from 1 orange to make 1/2 teaspoon peel; set aside. Halve orange; squeeze juice. Working over a bowl to catch the juices, peel and section the remaining oranges; set aside. Combine the juices to make 1/3 cup (add water, if necessary).
Rinse Brussels sprouts. Halve any large sprouts. In a medium saucepan cook sprouts, uncovered, in a small amount of boiling water for 10 to 12 minutes or until tender. Drain and transfer to a serving bowl. Gently stir in orange sections; cover and keep warm.
In the same saucepan melt margarine or butter. Stir in cornstarch and five spice powder or dill weed. Stir in reserved orange peel, orange juice, and mustard. Cook and stir until thickened and bubbly. Cook and stir for 1 minute more. Transfer Brussels sprouts and fruit to serving bowl. Top with sauce; toss to serve. Makes 5 or 6 side-dish servings.