What are some methods for parcooking hamburgers? Im trying to find a faster way to serve cheeseburgers. I was thinking maybe i could par cook 10-15 patties up to 90% done right before rush hour then store them in a steam table with beef broth, then place them back on the grill per order to finish cooking them. Does anybody have any better suggestions?
For speed and quality this is the perfect application for sous vide cooking.  You can cook burgers to varying degrees of doneness.  They can hang out in the water bath, at a degree or two below the rarest burger, for up to 2 hours.  Just quickly sear or grill to finish.