Prepare the livers by removing any buboes or green matter on the flesh, then soak them overnight in the milk to reduce any bitterness.
Heat the oil and then simmer the leek on a low to medium heat to soften and then caramelize the leeks, this should take about 5 minutes. Add the herbs and peppercorns and fry for a further 3-5 minutes.
Add the brandy and and ignite it with a long match, it should extinguish itself after a few moments and reduce down to a few tbsp, add the port and marsala and then boil for 10 minutes until you are left with 1/3rd the liquid. Remove from the flame and allow to cool slightly.
Add the livers, eggs, egg yolks and butter into the previous pan and stir gently, once the butter has melted add the salt and some fresh ground black pepper.
Transfer the mix to a blender or food processor and pulse until smooth ensuring that there are no lumps. Strain the mix through a sieve removing any sinew or lumps, pour 100ml into ovenproof ramekins and preheat the oven to 110°C.
Line a baking tray with kitchen towel and place the ramekins ontop, then pour hot but not boiling water around the ramekins being careful not to splash any water into them.
Place the parfaits in the oven and check them after 20 minutes, tilt them slightly to one side, the mix should buldge at the edge of the ramekin and wobble in the middle, if they are not ready put them in for a few more minutes.
Once done remove from the boiling water and allow to cool on the benchtop to near room temp, and then place them in the fridge for 4 hours to set.