Prick the chillies all over with a small sharp knife, and put them and the pepper directly over the flame of your hob, in a dry griddle pan or under a hot grill. You need to blacken them all over ( obviously the pepper will take longer than the chillies).
When they are blistered and black, and look ruined, pop them into a sandwich bag or a bowl covered with cling film to steam the skin off.
After about ten minutes peel away the skins, deseed them, and chop them fine. Stir into the mayo with a touch of sea salt and a squeeze of lemon juice.
Toss the meat with a good pinch of salt, pepper and the cayenne. Get two bowls, and put the buttermilk in one and the flour in the other.
Toss the meat into the flour, shake off the excess, then dip into the buttermilk, then back into the flour.
Pour the oil into a large pan or wok and heat until it reaches 180 degrees ( be careful!).
Cook the meat in batches and fry for about 3-4 minutes, then remove with a slotted spoon drain on kitchen towel and sprinkle with sea salt.