A glass dinner plate on a glass baking dish creates too much heat resistance. Three minutes in and it doesn’t show signs of popping.
A plastic lid set kitty-corner on a plastic container creates much less resistance. I suspect more of the kernels would have popped had they not been denatured by the previous attempt, but it’s enough for a snack.
The remaining kernels leave kernel-shaped indentations in the bottom of the plastic container when I scrape them out. I kind of wish I hadn’t eaten that popcorn now. It’s less tasty, somehow, in hindsight.
Hey NTS! It looks like those big plastic containers aren’t microwave safe.
… also, I should probably now say “that one big plastic container”.
Perhaps tomorrow I’ll ferret out some paper bags.