This is self explanitory really. You fill the inner compartemnt of the fridge door with any condiment and label the dispensers on the outside accoridngly. These could include
Ketchup, Mustard, BBQ, mayo, hotsauce, soy-sauce, tartare, sweet n sour, horserashish, wasabi, italian salad dressing, vinnagrette,
You could fill these detactchable/washable compartements with whatever you fancy.
Just push the lever on the fridge-door and voila!