Corn!

A lot of the comments below seems to assume it was a dried up piece of
corn that went through the wash cycle. The letter didn't specify this
so it could easily have been a piece of corn the fell off another
plate that the server was serving or accidentally dropped in the bread
from the kitchen serving table.

I cannot get over how many people think it's okay to give a dirty
plate to a customer - to have someone's food (that may have been in
someone's mouth) stuck to their plate.

Ugh. That's really disgusting.

If it was just a single piece of corn stuck on the plate, myself, I
would have just picked it off and continued on with the meal. Now if
it would have been a whole lot then that would have been a different
story.

I also don't understand why a lot of people get upset if there is food
stuck on the underside of the plate that is still stuck there after
washing. It's not like you eat on the underside of the plate, just
wipe it off and drive on.

Dishwashing is not perfect 100% of the time. Sometimes a stubborn
piece of food will stick. Although gross, nothing is warranted to make
your next experience more enjoyable, which I interpret as a request
for some sort of compensation. This issue could have easily been
resolved by any staff member at the restaurant. I work in lodging, and
we have a "compensation guide". Many issues are listed as apologize,
correct promptly, no compensation necessary. This is exactly what this
incident falls under.

Here's how to make your next experience more cleanly:

You hold up the plate and say to any server(doesn't have to be your
own server), "Excuse me. Can we have another plate, please?"

Did you mention this to someone while you were there? That would have
been the time to correct this issue and get some compensation, which I
gather you want. At this point, they only have your word about the
corn kernel.

The corn went through the wash and dry process and got baked onto the
plate. It's a mistake.