Shred cabbage very fine and cook 9 minutes in boiling, salted water.
Remove cabbage; drain well.
Place in buttered 1-1/2-quart casserole.
Melt butter in saucepan; stir in flour and salt until smooth.
Add milk gradually, continuing to stir until mixture thickens.
Pour this sauce over cabbage and sprinkle breadcrumbs over top.
Bake at 325 degrees for about 15 minutes or until crumbs are browned.