Cook asparagus in salted water until tender.
Arrange eggs and asparagus on crepes.
Season with salt and pepper.
Fold crepes and place in a shallow baking dish.
Cover with a foil top.
Heat at 350Â°F for 10 minutes or until warm.
To make'sauce, place yolks, salt, mustard and lemon juice in blender.
Cover and blend until eggs are well mixed.
Heat butter until bubbling hot and immediately pour butter in a tiny stream through small opening in top of blender, keeping blender on low until mixture is thickened, Spoon sauce over warm crepes.