Cornflower CORNING WARE Trio Set A33 Starter Set. In Unopened SEALED Box. Vintage Blue Cornflower Corning Ware is a Trio Set that includes. 1 Quart and 1 1/2 Quart Casseroles with 1 Plastic Lid and 1 Glass Cover 2 Quart Glass Covered Casserole. Hard to find set, especially NEW in sealed box!