Put self-raising flour into one bowl, and the buttermilk in one adjacent.
Dredge the thigh fillets in the flour and shake off the excess. Lay on a rack nearby.
Add half of the spicing to the flour and the other half to the buttermilk. Stir both to combine. Add 1/4 cup to the spiced flour and stir with a spoon to create a few lumpy bits in the dry mix (these will be delicious in the crust later).
Drop each thigh into the buttermilk, drain of excess, then drop into the lumpy flour and turn to coat well, pressing here and there to encourage sticking.
Heat your oil to 175°C and fry for 5 minutes or so- or until the thickest part of the chicken reads 75°C.
Drain on a rack over some kitchen towel.
Build your bun (or just eat with some pickles and beer).