Combine chicken breasts with water, salt, onion and celery and simmer until tender, about 30 minutes.
Remove from broth and cool.
Concentrate broth to 3 cups.
Heat butter in saucepan, stir in flour and let bubble.
Gradually stir in chicken broth and cook and stir until mixture boils and is thickened.
Taste and add more salt, if necessary.
Add cheese and stir until melted.
Meanwhile, trim and wash asparagus and cook in boiling salted water until just barely tender.
Arrange asparagus in bottom of buttered shallow casserole.
Remove chicken from bone in large pieces and place on asparagus.
Cover chicken and asparagus with cheese gravy.
Sprinkle casserole with crumbs.
Bake in a 425° F.oven for 15 to 20 minutes.