Stir together vinegar, oil and mustard in a large bowl. Set aside while cooking asparagus. Heat 2 in. water and half the salt to boiling in a large, deep skillet. Break or slice off the tough lower stems of the asparagus spears. Rinse and place half the spears in the boiling water. Cover and cook 5 to 6 minutes, or just until tender crisp. Transfer asparagus with tongs or a slotted spatula to the bowl with the vinegar mixture. In fresh boiling water, cook remaining asparagus with the rest of the salt. Transfer to the bowl with the vinegar mixture. Toss gently until spears are evenly coated. Place asparagus on a serving plate. Sprinkle evenly with cheese. Makes 8 servings. For a more sophisticated look, try shaving the cheese witha vegetable parer instead of grating it. If you like, garnish th platter with fresh orange sections. Approximate nutritional analysis: 41 calories per serving; 4 g protein; 6 g carbohydrate; 1 g fat (21% of calories); 3 g fiber; 159 mg sodium; 52% of the Daily Value for folic acid. From American Health June 1995 page 90. Submitted By ARLENES@HOLLY.COLOSTATE.EDU On