After I visited New York's popular restaurant, Momofuku, and enjoyed chef David Chang's ramen soup, I came home to recreate the dish. My recipe tester, Soo Kim, is Korean like Chang, so between us we came up with this very close version of his popular dish.
The broth used at Momofuku is a strong chicken/pork broth; I used plain chicken stock, which you can buy. You can also buy Chinese barbecued pork to substitute for the pork belly. Not as flavourful but still very good.
Momofuku cooks the eggs for the soup in a special apparatus that keeps a steady temperature of 140 C. I tried to do this in the oven and it didn't work. You can just poach a couple of eggs, set aside and add them to soup at the end to reheat.