Place steamer basket in large pot filled with 1 inch of water. Bring to boil. Add 1 pound trimmed asparagus, cover and cook until crisp-tender, 2 to 6 minutes.
In bowl, stir together 2 Tbsp mayonnaise, 1 Tbsp olive oil, 1 Tbsp white wine vinegar, and 1 tsp Dijon mustard. Season with salt and pepper. Drizzle over chilled steamed asparagus.