Your Tuesday Morning Brain Teaser!

It's time again for your 'Tuesday Morning Brain Teaser!'  It is designed to simply get your brain thinking on what I call the most boring day of the week.  You can enlist family, friends or co-workers to try and get the answer.  I have to warn you though, today's question is not as easy as it seems.

Here is today's 'Tuesday Morning Brain Teaser':

Pat Oliveri of Philadelphia invented what famous sandwich in the 1920's?

Good Luck!