To make the crepes: in a medium bowl sift flour and salt together.
Whisk in eggs and then stir in the milk.
Let crepe batter stand at room temperature for 1 hour.
Stir melted butter into crepe batter.
Heat a crepe pan or skillet (6-inch) over medium high heat.
Add one tablespoon clarified butter to pan, swirling pan to cover and then pour out any excess butter. Remove pan from heat.
Stir batter and then ladle 3 tablespoons of batter into the corner of the pan, tilt pan so batter will cover the surface evenly. Cook until bottom is brown, loosening edges with a knife; turn crepe and cook until other side is speckled brown. Slide crepe onto a plate and repeat with remaining batter; adjusting heat and adding more clarified butter if necessary. Cool and wrap crepes in foil. ***crepes can be prepared one day ahead and refrigerated.
To make the sauce: in a saucepan over medium low heat simmer the champaign and shallots until reduced by half (5 minutes).
Stir in cream, cooking until reduced to 2 cups (20 minutes) and then strain into a clean saucepan.
Preheat oven to 300- degrees F.
Rewarm crepes in the foil for 10 minutes.
Cook asparagus in a pot of boiling water until tender; drain.
Bring sauce back to a simmer and whisk in butter one tablespoon at a time and then season with salt and pepper.
Place one crepe on a plate, put 6 asparagus spears on crepe with tips alternating so 3 face each end and then top with 2 tablespoons sauce. Fold crepe in half over the asparagus. Repeat with remaining crepes, asparagus and sauce with 2 crepes per plate, spooning remaining sauce over crepes and garnish with parsley or chervil.