Dinosaur Sandwich

A man was driving across a desert. He spotted a deli in the middle of nowhere, in the middle of the day. The sign on top of the place said “Joe’s Deli. We cook whatever you want”. He felt challenged rather than compelled, and decided to go inside the restaurant.
He parked his car just outside in the dirt. He closed his vehicle and entered the joint. The deli was empty except for one man. He was reading a newspaper behind the bar. The man walked up to him and sat in one of the barstools.
“You must be Joe.”
“Nope,” answered the bartender.
“Then who are you?”
“I’m Joseph.” It was only then when the bartender put down the newspaper and gazed at his costumer.
“Well, hello Joseph.” The man gestured. “I read your sign outside. It said that you can cook me anything I want. I have a request.”
“It’s twelve o’clock. We open at one. Come back later.”
“Ok, but can I tell you my order now and you tell me if you can make it?”
The bartender scowled. “Shoot.”
“Ok, I want a Dinosaur Sandwich,” said the man.
The bartender grunted. “I won't make you a Dinosaur Sandwich.”
“HA! I knew you couldn't.”
“I can do it.”
“Then why don’t you do it?”
The bartender smiled back at the man. “You don't have enough money.”