I used to work for Hong Kong House (now Kim's Kitchen on Sandon Road) and Golden Gate on Stone Road for almost 2 years. I found that the
Golden Gate pays well, so ask there first!
Also, make sure you're insured for delivering fast food, as the police can fine you and crush your car if you're unlucky. I've known this happen a few times in Stafford. Adding fast food delivery onto your insurance may make it almost double the price, but it's worth it if you value your car.
...or alternatively work for Domino's or somewhere that provides you with a car (which is a safer option).