For the Asparagus:
Preheat your grill to medium heat, about 375° to 400°F.
Place the trimmed asparagus on a platter or baking sheet and brush with the olive oil, then sprinkle on the Provencal Seasoned Salt.
Place the asparagus across the grill grates perpendicular to the bars. Grill the asparagus with the lid closed for 5 minutes or until the asparagus is charred and tender, but not limp. Use tongs to turn the asparagus for grill marks.
Transfer asparagus to a platter and nestle watercress alongside. Arrange the grated eggs in a line across the center. For the prettiest "mimosa", lay the grated whites down first and arrange the grated yolks on top. Spoon the dressing over the salad.
Grated Eggs:
Separate the egg whites from the yolks. Using a sieve, gently push the whites through to "grate" them. Make sure to use a knife to scrape the bottom of the sieve to get all of the egg. Set aside the grated whites, and repeat process using the yolks. Set that aside, as well.
Lemon Herb Pepper Vinaigrette:
Whisk together the salt, vinegar and mustard. Then add the oil in a slow stream, whisking to emulsify.