You could cook the asparagus a day ahead, and make the salad hours before serving.
1. Preheat oven to 450 degrees. Trim, wash, and dry the asparagus. Spread them on a piece of heavy-duty foil, or a shallow baking pan. Drizzle with the one tablespoon oil. Season with salt and pepper. Roll around to coat. Roast about 10 minutes, or until barely tender when pierced with a knife. They should be quite firm. Remove from oven and cool; then cut into 1-1/2-inch lengths.
2. Simmer the potatoes in water to cover in a 6-quart pot for 15 minutes, or until tender with a little firmness at the center. Peel and cut into 1/2-inch pieces. Turn into a large bowl.
3. Gently fold in the onion, 1/4 cup vinegar, salt, pepper, and 3 tablespoons oil. Let stand 30 minutes.
4. Just before serving, gently fold in the asparagus. Taste for tartness (potatoes mute vinegar very quickly), and salt and pepper. Add more vinegar and seasonings if necessary. Fold in the herbs. Serve at room temperature.
Copyright 2001 by Lynne Rossetto Kasper
Lynne Rossetto Kasper has won numerous awards as host of The Splendid Table, including two James Beard Foundation Awards (1998, 2008) for Best National Radio Show on Food, five Clarion Awards (2007, 2008, 2009, 2010, 2014) from Women in Communication, and a Gracie Allen Award in 2000 for Best Syndicated Talk Show.