1. In a blender, combine the lemon juice, mustard, and artichoke bottom. Process until smooth. With the blender running, gradually drizzle in the oils in a thin stream. Season to taste with salt and pepper.
2. In a large bowl, toss the mache with the dressing. Pile the salad onto 12 individual salad plates. Top each salad with a slice of foie gras. Place the cherry tomatoes and asparagus tips decoratively on the front of plate. Sprinkle with the chives.