Drain asparagus, reserve half a cup of the liquid. Melt butter over low heat, add flour, stir until smooth, cook for 1 minute.
Gradually stir in milk and reserved asparagus liquid, stir until the sauce boils and thickens. Add the grated cheddar cheese and mustard, stir until cheese has melted. Season with salt, pepper, and nutmeg.
Add asparagus and chopped hard-boiled eggs to sauce.
Place in oven proof dish, sprinkle top with combined bread crumbs and the extra grated cheese.
Bake uncovered in moderate oven for 15 minutes or until golden brown.