Preheat oven to 450°. Arrange asparagus in roasting pan; drizzle with olive oil. Roast 12 minutes or until asparagus are crisp-tender.
Meanwhile, blend Knorr® Hollandaise sauce mix with milk in small saucepan. Add margarine. Bring to a boil over medium heat, stirring constantly. Reduce heat to low and simmer uncovered, stirring constantly, 1 minute or until slightly thickened. To serve, pour sauce over asparagus.