Mix the chicken with the buttermilk, garlic, herbs, season to your taste and the chilli sauce if using. Refrigerate for 8-24 hours. Remove from the fridge for 1 hour before frying
Combine all of the flours with a big pinch of salt
Carefully heat a deep pan with enough oil to fully submerge the chicken. Add a thin slice of ginger or onion, and when they start to turn brown it will be ready to fry
Remove chicken from the marinade and dredge the chicken directly into the flour mix or bread crumbs, coating each piece well, and fry in batches of about 3 pieces without crowding the pan for about 3-4 minutes, until cooked through and golden brown
Drain on kitchen roll and repeat with the remaining chicken pieces, then serve immediately inside the rolls with the tomato, lettuce, onion and pickles and hot sauce if using.