Several other national restaurant chains have added small hamburgers to their menu, but with the exception of the tasty tiny burgers I have eaten at two different Ruby Tuesday’s, they were just plain awful. The phony sliders, or whatever they were called, were over cooked, over seasoned, covered with onions more steamed than caramelized, and served on cold buns.
I know that there are at least a few non-chain burger joints that make a decent "slider", the Chicago Hamburger Company (CHC) in Phoenix comes to mind. Their "sliders' are good, and if you are in Phoenix, and need a "slider" fix the CHC is the place to go.
The “true” slider includes a small perforated patty, caramelized onions, steamed bun, and yellow mustard. The perforations in the patty make for quicker cooking, and facilitate onion flavor infusing into the patty. The small cardboard boxes that sliders are traditionally served in help keep the product warm, and also function much like the paper wraps used in other quality burger joints by helping the bouquet of beef/onion to permeate the bun.
White Castle and Krystal Burger are the places of choice for real sliders. Two or three sliders, a cup of chili with diced onions, and a cold soda; now that’s good eating.