In a frying pan heat up 2 tbsp of the butter and add the kimchi and gochujang. Fry for about 4 minutes on medium heat.
Add the liquid from the kimchi, remaining butter and the udon noodles and cook for another 2-3 minutes. If the noodles seem too dry add some additional water.
Serve topped with sesame seeds, spring onion (cut into small rings) and egg.