Although raw asparagus might seem unusual to those who have only eaten asparagus cooked, it is delicious.
With a sharp knife, cut asparagus diagonally into very thin slices and transfer to a large bowl. Halve large mushrooms. Slice mushrooms very thin and add with radishes to asparagus. Toss salad gently.
In a small bowl, whisk together lemon juice, mustard and salt. Add oil in a stream, whisking, and whisk until emulsified, or combine with a handheld blender. Drizzle dressing over asparagus salad and toss gently.
Spread watercress or spinach on a platter and top with asparagus salad. Grind pepper over salad. With a vegetable peeler, shave Parmesan into large curls over salad. 6 servings.
From Gourmet magazine