BM, following up on your suggestion, I bought a pyrex 2-qt lidded casserole dish, a jar of Orville's popcorn and a bottle of Orville's butter oil. I'll try them all out Christmas Day.
By the way, I introduced Orville Redenbacher's to my college campus! In 1969 I lived in New Orleans when not at school, and that summer New Orleans was a test market for Orville's. I loved it, so I got a popcorn maker and brought a jar of Orville's back to school with me. The picture of Orville on the label was exactly the same it is today, except that he had a crew cut!!!
One more detail: leave the lid slightly ajar to let steam escape.