Cook frozen cauliflower as directed until barely tender; drain. Arrange in baking dish, wedge cut slices of two hard boiled eggs. Pour sauce composed of 1 1/2 cups medium white sauce, 1 cup shredded medium sharp cheese, and 1 teaspoon of prepared mustard over cauliflower and eggs. Sprinkle with buttered bread crumbs. Bake at 375 degrees for 20 minutes.