Begin by butterflying your 2 chicken breasts so you end up with 4 pieces of chicken
Add your chicken in to a dish along with the buttermilk and gochugaru, clingfilm and place in the fridge to marinate for 2-3 hours (the longer the better!)
In a large and shallow bowl combine the ingredients for the gochujang sauce and set aside.
To make the coleslaw combine all the ingredients for it and stir well! Place in the fridge until ready to use.
Preheat a pot of rapeseed oil on a medium heat
For the dry batter mix together the cornstarch, plain flour, gochugaru, salt and pepper. To batter the chicken, allow the excess wet batter to drip off of the chicken before coating in the flour mixture.Mkae sure to press the dry batter into the chicken really well and shake off the excess before putting straight into hot oil to fry.
Fry on a medium-low heat for 7-8 minutes or until golden brown. if you're unsure as to whether the chicken is cooked through properly then I suggest getting your hands on a cooking thermometer. The internal temperature of cooked chicken is 75º or 165ºF. I use the Salter Instant read thermometer.
Toast the brioche buns with a little bit of butter until golden brown.
Burger compilation: on the bottom bun add a generous amount of coleslaw, the fried chicken and top bun. Then all that's left to do is enjoy!