Asparagus Vinaigrette Salad

1. Put two dinner plates into the freezer.
2. Lay the asparagus in a steamer basket. Put ½ inch of water into a large pot and bring to a boil. Carefully put the steamer basket into the boiling water, cover, and steam for 3 minutes, or until the spears are bright green in color.  Don’t overcook! (Pencil-thin spears cook quickly; thumb-thick ones require 1 to 2 minutes more. Avoid wilting the spears.)
3. Remove the plates from the freezer and immediately transfer the asparagus onto them, spreading the spears so that they do not overlap. Set aside to cool. (Do not plunge the asparagus into cold water; this often leaves it waterlogged.) Or cover and refrigerate for 1 to 2 hours before serving.
4. Mix the spinach and parsley and arrange them in a bed on a large platter. Season with salt and pepper. Lay the asparagus spears over the greens. 
5. Drizzle with 1⁄4 cup of the vinaigrette and top with the egg, croutons, and Parmesan cheese, if using. Pass the remaining vinaigrette at the table.

Combine the vinegar, mustard, garlic, and brown sugar in a bowl and whisk well. Add the olive oil in a slow, steady stream, while whisking. Add the salt and pepper, to taste, continuing to whisk.

Note: Alternatively, combine all of the ingredients in a small jar with a tight lid and shake it vigorously. Taste and adjust the seasonings, if desired.

Variations on Mustard Vinaigrette:

Tomato Vinaigrette: Whisk 1 tablespoon of tomato paste into Mustard Vinaigrette after adding the olive oil. Taste and adjust the seasonings with a pinch of brown or regular sugar, if desired.

Herb Vinaigrette: Add up to 1 tablespoon of chopped fresh or 3/4 teaspoon of dried basil, oregano, or thyme to Mustard Vinaigrette when you add the salt and pepper.