Pastrami burger consists of a toasted sesame seed bun filled with a beef patty that is topped with pastrami, cheese, tomatoes, shredded lettuce, onions, and fry sauce – a combination of ketchup, mayonnaise, sweet relish, and onion powder.
It's an invention of a Greek man named James Katsanevas, who had a restaurant called Minos Burgers in Anaheim, California, and started serving the dish in the early 1970s, while pastrami was brought over to Los Angeles by the Jewish people who came over from New York City in the middle of the 20th century.