Add the beef shins to a lightly oiled heavy-bottomed shallow casserole dish on medium heat. Sear the meat for about 45 seconds to a minute on each side. Take the shins out of the pan and set aside.
Add the sliced onion, grated fresh ginger, garlic and the gochujang chilli paste. Stir it all together for about 4-5 minutes to start everything caramelising in the pan.
Pour in the rice wine vinegar, soy sauce and dark brown sugar. Reduce for a further 2-3 minutes. Add the grated pear (or apple) into the pan along with its juice.
Place the beef shins back into the dish and pour over the red wine. Simmer on the hob for ten minutes before placing in the oven on low heat at 150-160℃/302°F-320°F for about 3 and ½ hours. If you don’t have time you can cook for 2 and ½ hours at 170-180℃/338°F-356°F.
Remove the dish from the oven, take the shins out and place them onto a chopping board, remove the bones and discard, and pull the beef apart using two forks to shred the meat. Stir the pulled beef back through the sauce which will have thickened to a ketchup-like consistency. (if not, reduce the sauce by itself until thick enough before adding the meat back in)
Make the slaw by combining the cabbage and mirin.
Pour a little olive oil into a frying pan and on medium heat, fry the eggs until the white is cooked but the yolks remain soft. Fry easy-over if preferred.
Lightly toast each brioche bun in the oven for a few minutes before ready to serve, build each burger with the slaw on the base of the brioche, then an equal portion of the pulled beef followed by a poached egg and a sprinkling of sesame seeds. Place the top of the brioche buns on top and serve immediately.