To be honest, the potato rambling sounds more interesting than whatever topic you originally had to write about.

Luckily it was just potatoes. I can only imagine what half the commenters here would have been mumbling about.

I hope your teacher likes them French-fried pataters. Or vodka.

So correct the essay and explain what happened. You both will have a laugh and move on.

Out of all the things you could have rambled about, potatoes is far from the worst...

I’m sure you’d get an A if you finally settled that whole po-tay-to/po-tah-to thing. Just “calling the whole thing off” is a cop-out that just lets the issue fester for future generations.

Now that's what I call a hot potato!