Cook asparagus according to directions on package, saving cooking water. Make white sauce of the butter, flour, milk and asparagus liquid. Remove from heat when smooth and thick. Add cheese and stir until melted. Place cooked asparagus spears, sliced eggs and cheese sauce in alternate layers in buttered 7 X 28 cm baking dish. Top mixture with lightly crushed corn flakes mixed with melted butter. Bake in 180ºC oven for 30 minutes.