Get a small saucepan and heat the water, sea salt, sugar, black peppercorns, bay leaves, fennel seeds, and red chillis. Stir until the sugar and salt have dissolved and bring it all to a gentle simmer.
Remove it from the heat and allow it to cool completely.
Add lemon juice and onion to milk and stir it throughly, before adding the cooled infused brine.
Place the skinned chicken in a bowl and pour over the brine - it'll need to cover the whole chicken of course so play around with bowl sizes if any chicken bits are left high and dry.
Leave the chicken in the fridge to brine merrily away for around 24 hours. Take out of the fridge at least 2 hours before you want to fry it to let it come up to temperature.
The next day, whisk together the dry ingredients for the breading and the eggs and bourbon.
Remove the chicken from the brine and let it drip dry.
Add the seasoned flour to a big tray and roll the chicken in it, coating the whole thing in flour. At this stage, if you have one, place a meat hook through the ribs of the chicken - this'll make it a lot easier to handle in the next few steps.
Hang it up to hydrate a little - you can tell this is happening as the flour will start to look wet.
Take around 5 tbsp of the egg mix and splash it all over the flour, using your finger tips to gently move it around to make small crags of flour - all important for that uneven crunchy coating you're aiming for.
Take the chicken and dip it in the remaining egg/bourbon mix, making sure it's evenly coated, then gently roll the chicken around in the flour. This takes some practise but try and do it as gently as possible and press the craggy bits of flour into it to get a really ragged effect.
At this point, if you have use a meat hook, hang it up - preferably in a fridge (big ask I know), but if not then somewhere cool and dark hanging over a tray where it isn't going to cause a sanitation nightmare. If you don't have a meat hook then place it on a rack over a tray in the fridge. Leave it for 3 - 4 hours to hydrate again.
Place the chicken into the egg again and into the flour one last time. Leave it hanging/on a tray to hydrate for around 30 mins while the oil heats up to 170°C.
Place in the hot oil for 20 - 30 minutes - try and place it breast side down so it cooks quicker. Keep checking the temperature of the oil and try and keep it at 140°C.
Meanwhile, add the melted butter to the hot sauce and whizz up in a blender - be careful to do this only for a few seconds as you can overwhip it and cause it to split.
When the inside of the chicken registers as cooked with a meat prob leave it to cool on a wire rack to prevent it going soggy, then serve it lashed with the sauce. It should be so tender that legs and wings can be ripped off at will.