I'm redirecting 25% of my portfolio to Domino's Pizza!
If one could get a concession in the Pentagon, think quality. Not totally outrageously expensive, just "very good", day in, and day out. And price it accordingly, remembering, daily or weekly repeat customers. It can't be too high flying & pricey, and conversely, don't serve 'em up the lowest common denominator, either.
I volunteer to supply the espresso. Once they tried mine, I'd be granted the needed security clearance, lol.
In recent years the preference is for Papa Johns