Is it Onions or Cabbage on a White Castle Slider?
White Castle 100% USDA inspected beef hamburger patties are steam grilled on a bed of rehydrated onions. The variety of onion is a California dehydrator onion and is very similar to the kind of dried chopped onions available in the spice aisle of any major grocery store. White Castle switched from fresh onions to rehydrated onions during World War II when onions and other fresh produce were hard to procure due to rationing. There is no cabbage (or turnips) used in a White Castle hamburger sandwich.