I'm sorry, but a steak sandwich is not a burger either, though it fits that definition you posted because they do not really qualify what a patty is. It has to be ground meat in my opinion. Anyone posting a tofu burger on this site deserves a DQ, and possibly even a spanking. (just kidding, post a tofu burger if you really want to)
This rule will be posted on all future Throwdowns, and is effective immediately in this Throwdown as well:
The dish must fit the category. Please do not submit something that does not match the category. I will personally oversee the entries, and if an entry does not fit the category in it's most fundamental form as I understand it to be, the entry will be disqualified. There will be no appeals process, however I promise to be as fair as I possibly can in regards to enforcing this rule. So please be mindful of the category when submitting your entry. Feel free to ask questions if you have questions about what would or would not qualify.