Originally Posted by
TheKeeper
So literally, there is no other way to get an in n out burger with other ingredients on it? Only real options are lettuce, tomato, onion and cheese?

You can have the onion grilled.
I'm not trying to dissuade you, they make very good basic burgers made out of fresh ingredients; however, in my opinion, In-N-Out offers nothing that justifies my going out the way for.
(Putting on my flame retardant suit)