To prepare the dressing: In a small bowl, combine the vinegar mustard, cumin, and sugar; season with salt and pepper. Whisk to blend. While whisking, slowly drizzle in the olive oil, mixing until the vinaigrette is emulsified. Set aside.
To prepare the salad: Fill a medium bowl with 2 cups of ice cubes and cover with cold water. Bring a pot of salted water to a boil over medium-high heat. Add the asparagus and blanch until tender but not mushy, about 3 minutes. Drain the asparagus in a colander and transfer to the ice water bath to stop the cooking. Drain again and place on a paper towel-lined plate to dry. Cut the asparagus stalks into thirds.
In a large mixing bowl, combine the blanched asparagus, parsley, artichokes, tomatoes, and watercress. Whisk the vinaigrette to combine and pour over the salad. Toss to coat and serve.
Recipe courtesy of Ingrid Hoffmann, 2008