Over here at McDonalds, the kitchen crew makes up the burgers as the orders come in. They have trays of all the parts, and just make them up to order.
It's crap food, but it just makes me feel so special.
eta: I don't like BK (Hungry Jacks here). I find their burgers pretty bland. I'm not a big fan of McDonalds either, but if I had to choose I'd go with McD's.