Bjorn van der Horst and Omar Romero plan to pay a flat salary they open Kojawan in London’s Edgware later this year. By banning the addition of tips to bills paid by card Horst & Romero intend to bring back the idea that working front of house is a vocation. With the flat wage plus cash tips staff at the Kojawan Korean-Japanese restaurant will be able to earn a competitive London wage. “You don’t have to feel obliged to give a tip. They are fairly paid. You will not be able to leave tips with a card, because then we’d have to create some system for that pot. Will it…