Preparation Whisk first 6 ingredients in medium bowl. Season with salt and pepper. Cook pasta in large pot of boiling salted water until almost tender but still firm to bite. Add asparagus and cook until crisp-tender, about 2 minutes longer. Drain, reserving 1/4 cup cooking liquid. Rinse with cold water until cold. Drain well. Transfer pasta and asparagus to large bowl. Add green onions and smoked salmon. Mix reserved cooking liquid into dressing. Add to salad; toss to blend. Season with salt and pepper. Chill at least 1 hour and up to 6 hours.
Preparation Whisk first 6 ingredients in medium bowl. Season with salt and pepper. Cook pasta in large pot of boiling salted water until almost tender but still firm to bite. Add asparagus and cook until crisp-tender, about 2 minutes longer. Drain, reserving 1/4 cup cooking liquid. Rinse with cold water until cold. Drain well. Transfer pasta and asparagus to large bowl. Add green onions and smoked salmon. Mix reserved cooking liquid into dressing. Add to salad; toss to blend. Season with salt and pepper. Chill at least 1 hour and up to 6 hours.