Tie celery, parsley, tarragon, and bay leaves into a bouquet garni.
Fill a fish kettle halfway with cold water and add aromatics, vegetables, asparagus trimmings, and seasoning.
Place salmon in the kettle, cover with water if needed, bring to boil, then remove from heat.
Boil asparagus spears for 1-2 minutes until tender, then refresh in ice-cold water.
Whisk egg yolks in a bowl over simmering water until pale and thick.
Slowly whisk in warm clarified butter to create a smooth emulsion.
Stir in white wine vinegar and season the sauce with salt and pepper.
Serve the fish with blanched asparagus and a spoonful of hollandaise sauce.